The Packaging Glossary

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Abrasion: Scuffing or wearing of a part against its package or vice versa. Scuffing of a package against external surfaces. The damage caused by friction such as rubbing, scuffing, or scratching.

Abrasion Marks: Marks on a photographic print or film appearing as streaks or scratches, caused by the condition of the developer.  Can be partially removed by swabbing with alcohol.

Abrasion Resistance: Ability to withstand the effects of repeated rubbing and scuffing.  Also called scuff or rub resistance.

Abrasion Test: A test designed to determine the ability to withstand the effects of rubbing and scuffing.

Abrasiveness: That property of a substance that causes it to wear or scratch other surfaces.

ABS: Acrylonitrile Butadiene Styrene is a thermoplastic copolymer that can withstand high temperatures and has good adhesive properties. It is one of the most widely used engineering thermoplastics. ABS extrusions are mainly used for indoor purposes. The plastic product has excellent surface appearance, strength and stiffness, toughness and chemical resistance, as well as processing ease and versatility. ABS is often used for refrigerator door liners, interior automotive trims, and housings for business machines, small appliances, telephones, and other consumer electronics. Furthermore, ABS offers a broad processing window with resins tailored for plastic extrusion manufacture, injection molding, sheet extrusion and coextrusion, plating, roto molding, compression, cold forming, and blow molding.

 Absolute Humidity: The actual weight of water vapor contained in a unit volume or weight of air.

 Absorbent: a substance that can retain other substances when in high relative humidity atmospheres.

 Absorption and Drying: Absorption is the property that causes a material to absorb liquids or vapors in contact with paper. The absorption and drying properties of paperboard are crucial for achieving a perfect result when printing and varnishing. The measurable properties normally related to absorption and drying are ink absorption and surface pH. Both are strongly influenced by the constituents of the coating and the uniformity of the coating characteristics.

  • Good absorption and drying properties come from the use of virgin fibers, the formation and treatment of the baseboard, and the coating properties (quality, formulation, application method, smoothness, and finishing). The printing and varnishing results depend greatly on both the baseboard and the coating having very uniform absorption and drying characteristics.
  • Ink absorption is the ability of the paperboard surface to absorb ink optimally. If too much pigment is absorbed this leads to less bright color reproduction. If the absorption is too slow, there is a risk of set-off.
  • The correct level of pH is important for the ink-drying process. Normally a pH level between 6 and 8 is required. A pH level of 5 is too low to be optimal.
  • There is an important connection between the absorption and drying processes. Depending on the printing method, the fluent ink vehicle can be dried either by evaporation or by chemical change as follows:
  • When the ink vehicle consists of water or organic solvents (e.g. alcohols, esters, or ketones) the vehicle is dried by evaporation. Hot air or infrared dryers (IR dryers) can be used.

  • When the vehicle consists of organic oil (e.g. linseed oil) the first step in the drying process is absorption (ink setting). After that the drying process continues by chemical change, i.e. oxidation polymerisation of the oil.

  • There are also inks and varnishes that dry virtually instantaneously on the press or varnishing machine by the use of ultraviolet radiation (UV drying). In this case the drying is a chemical cross-linking polymerisation process.

 Acceptable Runner/Cavity Ratio: Runner systems designed for high pressure drops to minimize material usage and increase frictional heating in the runner.

Acceptance Sampling or Inspection: The evaluation of a definite lot of material or product that is already in existence to determine its acceptability within quality standards.

Accelerate: In flexographic printing, as by the addition of a faster drying solvent or by increasing the temperature or volume of hot air applied to the printed surface.  Electrical – To speed rewind shafts during flying splices, taking up slack in the web.

Accordion Fold: Bindery term for two or more parallel folds which open like an accordion.

Accumulator: groups packages together to hold them until they need to continue on the line

Acetone: A very active solvent used in packaging gravure inks; the fastest drying solvent in the ketone family.

Achievable Run Speed: Speed that was tested during commissioning and has a wastage factor of <0.01. It is generally 20% less than the packaging line capacity and 50-70% less than the packaging line capacity for true just-in-time packaging line.

A.C.L. (Applied Ceramic Labeling): Applied color lettering. Colored lettering or design of a ceramic nature fused onto bottles. Employs screen printing to transfer glass frit (powdered glass colorant) to the surface of a bottle or glass container. The design is fired, heated in a lehr, and becomes permanently fused.

Aclar: A barrier laminated film. Often used in packaging medications. The scientific name is Chlorotrifluoroethylene (CTFE).

Acrobat: Adobe’s Portable Document Format referred to as PDF.

Activator: A chemical used on exposed photographic paper or film emulsion to develop the image.

Activity: An individual step that is part of the total job being scheduled.

Actual Set Run Speed: The target speed/rate that is set for a given package run cycle on a per minute of per hour basis. This is usually set by the operator or management.

Additive: A material such as a hardener, softener, preservative, slip agent, etc., added to a base material in the form of a resin in order to achieve a specific result.

Additive Color: A color system in which colors are made by combining (adding) all three primary colors of light, RGB. Different proportions of the three colors of light produce different colors.

Additive Primaries: In color reproduction, red, green and blue.  When lights of these colors are added together, they produce the sensation of white light.

Adhesion: 1) The sticking together of any two materials, e.g., adhesion of ink to paper or film.  2) The attractive force that exists between an electrodeposit and its substrate that can be measured as the force required to separate the two.

Adhesive Lamination: A laminating process in which individual layers of multi-layer packaging materials are sandwiched together with an adhesive.

Adsorb: To attract and hold molecules on a surface, e.g. solvent molecules in a solvent recovery adsorption bed.

Aerosol: A gas-tight container equipped with a valve which is designed to hold the product and the propellant gas under pressure. When the valve is opened, generally by finger pressure, the product is dispensed. Aerosol products include wet sprays, foams, pastes, syrups and powders.

Affordable capital limits (ACLs): The specified cost for a project to achieve maximum value.

After-Tack: Tack that develops after ink has apparently dried or after a heat-drying operation.

Against the Grain: Folding or feeding paper at right angles to the grain direction of the paper. Also called crossgrain.

Age Resistance: Shelf Life:  The resistance to deterioration by oxygen and ozone in the air, by heat and light, or by an internal chemical action.

Age Stability: A test to determine whether an ink formulation can withstand a specific temperature for a specified period without change.

Agglomerate: to gather into a rounded mass; cluster densely

Agglomeration: A cluster of undispersed particles.

Aging: The physical and/or chemical change of a material with respect to time, under defined environmental conditions, leading to improvement or deterioration of properties.

Airbrush: In artwork, a small pressure gun shaped like a pencil that sprays watercolor pigment. Used to correct and obtain tone or graduated tone effects. In offset platemaking, a pumice used to delete unwanted areas. In electronic imaging, a retouching technique. This technique disappeared as film disappeared, and is now done with image editing programs.

Air-Flow: Air-Flow is used in agricultural product packing and has die cut holes to reduce spoilage and ensure even cooling. Air-Flow replaces pallet netting and gives users all the advantages of conventional LLDPE Pallet Stretch Wrap, which include strength, load-holding and ease of use.

Airshaft: A device used for handling winding reels in the processing of web-fed materials, such as continuous-process printing presses.

Alcohol: A series of organic compounds characterized by the presence of the hydroxyl group; volatile solvents, the most common being ethyl alcohol.

Aliphatic Solvents: Saturated hydrocarbon solvents derived from petroleum, such as hexane, heptane and VM&P naphtha, used primarily in A-type gravure inks, or as diluents for other inks and coatings.

Allocated Inventory: Materials that are in inventory or on order but have been assigned to specific production orders in the future. These materials are not available for use in other orders.

Alkaline Paper: Paper made with a synthetic alkaline size and an alkaline filter, like calcium carbonate, giving the paper over four times the life (200 years) of acid sized papers (40-50 years).

Alkali Resistance: Property of an ink, coating or substrate so that it resists film breakdown, color change or color bleed when printed material is subjected to contact with alkaline materials such as soap or detergent.

Alloy: A term used in the plastics industry to denote blends of polymers or copolymers with other polymers or elastomers. – i.e. ABS/Polycarbonate.

Alteration: Change in copy of specifications after production has begun.

Alumina Hydrate: Also known as hydrate. A white, inorganic pigment used as an extender in inks; noted for its transparency.

Aluminum: A metal refined from bauxite ore into ingots by electrolysis. The ingots are rolled into thin sheets of foil or drawn and formed into can bodies. Foil may range in thickness from 7 to 150 microns.

Aluminum Coating: A coating composed of aluminum paste or powder and a mixing varnish or vehicle.

Aluminum Foil (AL): A thin gauge (6-12 microns) aluminum foil laminated to plastic films to provide maximum oxygen, aroma and water vapor barrier properties. Although it is by far the best barrier material, it is increasingly being replaced by metallised films, (see MET-PET, MET-OPP and VMPET) because of cost.

AM (Amplitude Modulation): Halftone screening, as opposed to FM screening, has dots of variable size with equal spacing between dot centers (see halftone).

Amber: A brown color of glass that absorbs nearly all radiation with wavelengths shorter than 450mm. Amber glass offers excellent protection from ultraviolet radiation. This is critical for products such as beer and certain drugs.

Ambidextrous Control: Separate right/left hand braking control which allows the operator to have total stretch control over 100% of the surface area of the stretch film while wrapping.

Ambient Temperature: The temperature of a medium surrounding an object. The term is often used to denote prevailing room temperature.

Amorphous: Devoid of crystallinity or stratification. Most plastics are amorphous at processing temperatures. Material assumes more random molecular structure when cooling.

Ampul: Also ampoule, ampule, ampoul. A relatively small container made from a glass or plastic tube, the end of which is drawn into a stem and closed by fusion after filling. The bottom may be flat, convex or drawn out as required. Opening is achieved by breaking the stem.

Anchor Coat:  A coating applied to the surface of a substrate to effect or increase the adhesion of subsequent coatings.

Anchoring:  In flexographic printing, term describing process of bonding or fusing inks to the substrate.

Angle of Wipe:  In gravure and flexographic printing, the angle the doctor blade is set from the centerline of cylinder, before loading.

Angel Hair: Thin strands of film left on the edges of rolls caused by improper bologna slicing.

Aniline Dyes:  Derivatives of coal tar classified by chemical composition.  Basic dyes have extreme brightness, but are not fast to light, while acid dyes are less brilliant, but are faster to light.

Aniline Printing:  Early name for rubber plate printing, using fast-drying fluid inks. Now obsolete.

Anilox Inking:  In flexography, two-roll inking system. A smooth fountain roll transfers inks to an etched metal or ceramic-coated metal roll with cells of fixed size and depth that then transfer the ink to the plate.  Also used in keyless offset.

Anilox Roll:  Mechanically engraved steel and chrome-coated metering roll used in flexo presses to meter a controlled film of ink from the contacting elastomer-covered fountain roller to the printing plates which print the web.  Volume of ink is affected by the cell count per linear inch and dimension of the cell and cell wall of the engraving.  Manufactured from copper and chromium-plated steel.  Also given a coating of aluminum oxide (ceramic) or copper and chrome.

Anilox Roller: A special roller that transfers ink to the image carrier in flexographic printing. The cylinder has a regular grid pattern of small cells.

Anilox System:  The inking system commonly employed in flexographic presses, consisting of an elastomer-covered fountain roller running in the ink pan, adjustable against a contacting engraved metering roll, the two as a unit adjustable to the printing plate roll, design roll, or plain elastomer coating roll as the case may be.  Ink is flooded into the engraved cells of the metering roll, excess is doctored off by the wiping or squeezing action of the fountain roll, or a doctor blade and that which remains beneath the surface of the metering roll is transferred to the printing plates.

Animal Healthcare Products: Glass and injection molded plastic items, such as open-tip syringes, nasal inoculation syringes and bolus dispensing guns, are available in USDA/FDA compliant and approved resins.

Anisotropy: The tendency of a material to react differently to stresses applied in different directions.

Anneal(ing):  Glass: A controlled heating and cooling process designed to relieve internal stresses introduced in a glass container during and immediately after glass container formation.

Plastic: The process of relieving internal stresses of molded plastic articles by heating to a predetermined temperature, maintaining this temperature for a predetermined length of time, and slowly cooling the articles.

ANSI: American National Standards Institute

Antifoaming Agent:  An additive used in ink that prevents or eliminates foaming of a liquid or breaks foam already formed.

Anti-halation Backing:  In photography, coating applied to back of film to prevent the spreading of light beyond its proper boundaries.

Anti-Offset or Set Off Spray:  In printing, dry spray of finely powdered starch used on press to prevent wet ink from transferring from the top of one sheet to the bottom of the next sheet.

Antioxidant: Additive used to reduce degradation from oxygen attack at normal or elevated temperatures. Sources such as heat, age, chemicals, and/or stress may accelerate oxygen attack.

Antiozonants: These additives are used to prevent the negative effects of ozone on the resin materials.

Anti-Skid Varnish:  A generally clear resin coating, formulated and applied to large flexible packaging to retard slippage during stacking and handling.

Anti-Stat: Contains an anti-static additive that dissipates static electrical charges. Good for short-term storage. Anti-Static and Static Shielding Bags

Antique Finish:  A term describing the surface, usually on book and cover papers, that has a natural rough finish.

Aperture: In photography, lens opening or lens stop expressed as a f/no., such as f/22.

Apochromatic: In photography, color-corrected lenses which focus the three colors, blue, green and red, in the same plane.

Application: The act of applying or putting to use. What the molded plastic article will be in its final form.

Applicator Cap: A container closure designed so that it may be used to apply the contents of the container, such as daubers or cleaners for oil and grease spots or daubers.

Applicator Rod: Short glass or plastic rod 2 mm to 4 mm in diameter used in conjunction with an applicator cap. The end which enters the cap is cut square. The other end may have a variety of glazed finishes.

Applicator Roll: Coating; print roll, tint roll, lacquer or varnish roll.

Aquatint: An early plate engraving method that created tonal variation by etching through granular material with varying concentrations of etchant.  Used only for fine art engraving.

Aromatherapy Packaging: Items used to package aromatherapy products, including glass and aluminum bottles, vials, perfume samplers and candle holders.

Art: All illustration copy used in preparing a job for printing.

Artboard:  Alternate term for mechanical art.

Artificially Balanced Runner System: Balancing a runner system by adjusting the pressure drop of a long, large diameter runner against a short, small diameter runner. Since pressure drop over the small diameter runner will be much more affected by heat loss than the large diameter runner, an artificially balanced runner system will work within a set range of molding conditions. The width of this range of molding conditions determines the stability of the molding.

Art Director:  The individual responsible for overseeing the creative and production process and managing other creative individuals.

Ascender:  That part of a lowercase letter that rises above the main body, as in “b”.

Aseptic Packaging: A technique for creating a shelf-stable container by placing a commercially sterile product into a commercially sterile container. The process involves sterilizing a product and its intended container (usually separately) and then bringing them together within a sterile environment for filling and sealing. The sealed container is designed to maintain a sterile product until the seal is broken. In addition, when packaged aseptically, the product does not require refrigeration until the package seal is broken. Used for drink boxes, wine (bag-in-box), tomato products and soy milk.

Ash Content: The solid residue remaining after a substance has been incinerated or heated to a temperature sufficient to drive off all combustible or volatile substances.

Aseptic processing and packaging: The filling of a commercially sterilized cooled product into presterilized containers, followed by aseptic hermetical sealing, with a presterilized closure, in an atmosphere free of microorganisms.

Aspect Ratio: Ratio of total flow length to average wall thickness.

Asphaltum (Asphalt):  A dark colored resinous substance soluble in hydrocarbon solvents.  Used as a moisture barrier in heavy laminations.

Assembly: A wide variety of assembly services such as collating, filling, gluing, labeling, bagging, shrink wrapping, bag sealing, blister sealing, display assembly, package assembly, inspection, and bulk mail preparation are available. Some companies follow strict anti-contamination procedures to ensure a clean pack.

A-stage: This is a very early stage in the reaction of certain thermosetting resins where the molecular weight is low and the resin is still soluble in some liquids and still fusible.

ASTM: Abbreviation for American Society for Testing and Materials.

Atomizers: Various styles of atomizers and purse sprayers are available, including metal, aluminum, molded glass, plastic, and pastel enamel.

Author’s Corrections:  Also known as “AC’s”. Changes and additions in copy after it has been typeset.

Auto Bander: Jumbo rolls of stretch film for automatic bundling equipment. Stretch Film and Wrap.

Autoclave: A pressure vessel into which steam or other vapor can be introduced at a suitably high temperature to sterilize packages or other objects placed therein. Small autoclaves are normally used for sterilizing surgical instruments and supplies, laboratory glassware, media for bacteriological testing and similar materials. Large autoclaves are used for sterilization of liquids and solutions packaged in glass containers. The pressurized vessels used for production-scale sterilization of foodstuffs in jars or cans are called retorts.

Automatic: A machine that runs without the assistance of an operator. Ex. Case sealer that closes and seals box

Automatic Processor:  In photography, machine to automatically develop, fix, wash, and dry exposed photographic film.  In plate making, machine to develop, rinse, gum and dry printing plates.

Adherence: The state of adhering. The strength or test specimen measured in such a manner that a large part of the loading stress is concentrated at or near the bond to produce an apparent fracture in the bond.

Adhesive: A material used to bond two surfaces together; i.e., hot melts, latex, or animal based glues. Any viscous substance such as an animal or vegetable glues, resins, dextrin’s or paste used in the manufacture and closure of folding cartons; or used to bond one material to another as in laminating. For corrugated, adhesives are usually starch or dextrin based.

Anti-oxidant Board: Boxboard chemically treated to increase the shelf life of foods containing fats and oils by retarding rancidity of such products when packaged in cartons made of it. The treatment does not change the appearance of the board and is non-toxic and odorless.

Anti-tarnish Board: Boxboard chemically treated to retard development of tarnish which may result from packaging non-ferrous items, such as brass and silver.

Aqueous (inks/coatings): Water based inks and coatings widely used in the industry, replacing solvent based materials to reduce or eliminate the use of volatile organic chemicals (VOC’s) from the converting process.


Backbone:  The back of a bound book connecting the two covers; also called the spine.

Backflow: Molten resin that flows back out of the mold, returning to the runners.

Backing Plate: A plate used as a support for the mold cavity block, guide pins, bushings, etc.  

Backing Up: Printing the reverse side of a sheet that has been printed on one side.

Backlash:  Lost motion. Alt:  Looseness in the teeth of a gear mechanism, permitting movement of one or more gears without corresponding movement in the connected mechanisms.

Back Liner: see Bottom Liner

Back Pressure: The resistance of the molten plastic material to forward flow. In molding, back pressure increases the temperature of the melt, and contributes to better mixing of colors and homogeneity of the material. However, as back pressure increases, so does cycle time.

Back Printing:  Printing on the underside of a transparent film.  Also called reverse printing.

Back-Trap Mottle: Non-uniform trapping of previously laid down ink film onto an offset lithographic blanket; mostly caused by non-uniform ink setting and/or incorrect ink tack sequencing in multicolor printing.

Back Up Roll: See impression cylinder.

Bad Break: In composition, starting a page with a one word line at the end of a paragraph (called an “orphan”) or ending a page or paragraph with a single-word line (called a “widow”).

Baffle: A partition or plate that changes the direction or restricts the cross section of a fluid, thus increasing the velocity or turbulence.

Baffle Mark: A bottom defect. A seam occurring between the baffle and the blank mold.

Bags on a Roll: Continuous roll of seamless tubing perforated under bottom seal. Bags must be torn off to open. Flat and Plastic Poly Bags on Rolls

Balanced Runner: A runner system designed to place all cavities at the same distance from the sprue.

Ballooning: A pillow effect created when air is trapped within a shrinking bag.

Band: A strip of paper or board wrapped around the top, bottom, and sides or ends of a package or other object to cover them without being turned in.

Banding: The presence of extraneous lines in a printed page. Banding generally occurs when a color printer needs to pass the print head over a page multiple times to print each color. If the page isn’t exactly lined up for each pass, lines may appear.

Banding / Bundling: Wrapping several items together with plastic stretch wrap. Stretch Film and Wrap

Bar Code: A way of labeling or coding a product with a series of lines and spaces that allows a clear description of the contents. Bar codes can only be read by scanners. UPC Bar code Information See also UPC.

Bare Cylinder Diameter:  The diameter of the actual plate cylinder, before the stickyback and plates are mounted.

Barrel: The section of a molding machine that contains the feed screw; also the section where resin heating and mixing occurs.

Barricade Tape: Non-adhesive warning films printed with standard text or custom logos.

Barrier Film: Specially formulated film, typically used to extend the shelf life of food products. Prevents the transmission of moisture and gases.

Barrier Material: Term used to prescribe one of two classes of specialized packaging materials that provide environmental protection to the package contents: (1) gas-, moisture-, or light-proof materials that control or eliminate the amount of these environmental constituents that pass into or out of a package; (2) a porous material possessing a structure that prevents the passage of microorganisms that might contaminate the contents of a package.

Base: Often used in reference to a full strength ink or toner.  Generally refers to the major ingredient used in a clear lacquer, varnish or ink.  May refer to either the solvent or binder system.  A cylinder before it is engraved.  Base film before addition of coating.

Base Box: U.S. standard unit of a quantity of tin plate. A base box equals 31,360 square inches of plate. The weight of a base box will vary with the thickness of the plate. Also used in the United Kingdom.

Base Ink: A single-pigmented ink with high pigment-to-binder ratio, used in packaging applications for blending.

Base Locking: The thick layer of film produced by manually applying stretch film at a 45 degree angle to the floor. This wrap helps lock the boxes to the skid to prevent shifting.

Basis Metal: The material upon which coatings are deposited.

Basis Weight: The specification of boxboard as density of weight per unit area. It is measured as “pounds per thousand square feet” in the U.S. and “grams per square meter” (gsm) in Europe. Paperboard normally refers to sheets of paper .012” (12 points) or more in thickness, although there are some exceptions.

Batch: A properly proportioned mix of raw materials melted to produce glass.

Bauxite: Aluminum ore.

Beach Test: A test for the puncture resistance and scoreline strength of boxes. The amount of penetration or resistance of the sample is indicated on a scale.

Bead: A narrow, round projection above or below the surface.

Bead Seal: A thin round weld, created when pressure and heat are applied to two layers of film.

Bearers: In offset, the flat surfaces or rings at the ends of the cylinders that come in contact with each other during printing. They serve as a basis for determining packing thickness.

Beater: A large mixer in which stock is prepared. The fibers are mechanically treated in the beater while additional ingredients are mixed in

Beater Dyed:  A paper, the pulp for which is colored in the beater.

Ben Day: A shadowing effect in printing derived from engravings made by a mechanical shading machine.

Bending/Folding: The capability of a piece of containerboard or combined board to be folded along score lines without tearing of fibers or structural weakening.

Bending Board: A mild upgrade from chipboard, still composed of mainly recycled pulp. This board contains more high quality fibers than chipboard so it can withstand more repetitive bending. Often, this type of board ranges from light gray to light tan.

Bending Chipboard: The least expensive grade of boxboard used in the manufacture of of folding cartons, composed principally of recycled fiber.

Bending Stiffness, Bending Moment, and Bending Resistance: Bending stiffness is the force required to bend a paperboard sample to 5º. The bending resistance is the force required to bend it to 15º, while the bending moment is the movement required to bend it to 15º.

Bent Finish: A finish defect. A finish which has a bent or crooked appearance. Also called “crooked finish”.

Bent Neck: A neck defect. A neck where the finish is tilted to one side, preventing filling of the bottle.

Bevel: Angle, ground, honed, or filed on edge of doctor blade.

Bezier Curve: The description of a character, symbol or graphic by its outline; used by drawing programs to define shades.

Bi-Axial Orientation: Oriented along both X and Y-axis. Biaxially stretched films are generally well-balanced in both directions and much stronger in terms of tear strength.

Billboard: 1) Term used to describe the front or face panel of a carton as it sits in the display rack. 2)The pop-up display panel of the typical counter display.

Bimetal Plate: In lithography, a plate used for long runs in which the printing image base is usually copper and the non-printing area is aluminum, stainless steel, or chromium.

Binder: Adhesive substance or other binding material whose function is to fasten or to hold components or materials together, such as coatings, sheet plies, or pigment.

Biocides & Fungicides: Additives that are used to inhibit the growth and colonization of fungus, bacteria, and other pests.

Biodegradable: The degradation of material from naturally occurring microorganisms, such as bacteria, fungi or algae over a period of time.

Bioplastics: Bioplastics, such as thermoplastic starch and cellulose-based plastics, are a form of plastics derived from renewable biological material sources. Biodegradable bioplastics are used for disposable items, such as packaging and catering items (crockery, cutlery, pots, bowls, straws). Bioplastics are more sustainable because they can break down in the environment faster than fossil-fuel plastics.

Bird Swing: An edge or side defect. A string of glass extending across the inside of the bottle.

Bit: In computers, the basic unit of digital information; contraction of Binary Digital.

Bitmap or BMP:  In computer imaging, the electronic representation of a page, indicating the position of every possible spot (zero or one). A computer graphics format not generally used in professional printing.

Black-and-White: Originals or reproductions in single color, as distinguished from multicolor.

Black Plate: The low-carbon steel base for tin mill products, which has been reduced to proper thickness, annealed and temper rolled, and is ready for processing into finished tinplate products or coating with organic finishes. Sometimes called Can Making Quality plate, or simply C.M.Q.

Black Printer:  In color reproduction, the black plate, made to increase contrast of dark tones and make them neutral.

Black Specks: A specific kind of inclusion/contamination often associated with heat-degraded materials.

Black Spots: A general defect. Small black specks in the glass.

Blade Coating: In gravure and flexography, the predominant method of applying coatings to paper, in which an excess of coating is applied to a cylinder and then wiped off with a blade; the excess coating is returned to a reservoir for reuse.

Blade Extension:  In gravure and flexography, the amount the backup and doctor blades extend beyond the holder, 3/8 to 1/2 inches.

Blade Line: When the doctor blade on a rotogravure press develops an imperfection causing a line or streak in the print.

Blake: A particular style of straight sided oblong bottle used primarily by pharmaceutical concerns. Also called space saver and wide mouth packer.

Blanching: Heating by direct contact with hot water or steam

Blank: A piece of material from which a package or a component can be made by additional operations. For example:

  • In closures, the basic cap before forming or threading.

  • In metal cans, the flat piece cut to size before forming into a body or end.

  • In paperboard, the cut and scored section before erecting and gluing to form a box, tray or lid.

Blanket: In offset printing, a rubber-surfaced fabric that is clamped around a cylinder, to which the image is transferred from the plate, and from which it is transferred to the paper.

Blanking: The action of separating out individual carton blanks from the waste or scrap portion of the master (production sheet). Typically performed as a second operation on a cutting press, the first operation being cutting and scoring a printed sheet.

Blanks: The mold parts used in all container machines for preliminary formation of glass or plastic in preparation for the most efficient completion of containers in the finish molds where bottles are blown. The blank forms the parison. The parison itself is at times referred to as the blank.

Blank Seam: An edge or side defect. A seam which is relatively large, extending from the shoulder to the bottom of the container. Also called “mold seam”. Blisters A general defect. Relatively large bubbles in the glass.  

Blast Finishing: The process of removing flash from molded objects and/or dulling their surfaces, by impinging upon them with sufficient force to remove the flash.

Bleached Chemical Pulp: Chemically processed virgin fibers are flexible and soft, and can therefore retain their original length and strength. The paperboard becomes very strong, with good creasing, embossing, and cutting properties, as well as low dust generation. When bleached, the chemical pulp provides paperboard with high whiteness, brightness, and good light stability. The pulp is also a clean product of known origin.

Bleached Paperboard: To make a truly white paperboard, all its components have to be white. Bleached paperboard is made from bleached chemical pulp.

Bleed: A printed space beyond the score edge to allow the design to be cut or folded.

Blind Opening: A collapsible tube neck with a metal diaphragm across its orifice for leak-proof packaging of liquids or pastes such as glues and cements. This diaphragm must be pierced or cut off in order to use the contents. Blind opening is also called blind end, closed end, or blind orifice.

Blister: 1) As related to the paper making process, a defect caused by air pockets in the paperboard or in the case of laminates or multi-ply paperboard, areas of poor or non-existent adhesion between plies. 2) In packaging terms, a thin bubble or dome of semi-rigid plastic attached to a piece of paperboard to form a package (blister pack).

Blister: An imperfection on the surface of a plastic article caused by a pocket of gas beneath the surface.

Blister Pack: A type of packet in which small items are displayed and sold, consisting of a transparent dome of plastic or similar material mounted on a firm backing such as a thicker paper, metal film, or thin cardboard backer

Blister Packaging: The item to be packaged is secured between a preformed transparent plastic “bubble” and a paperboard carrier. The bubble is commonly of thermoformed PVC or PET and the printed carrier often has a die-cut hole to permit hanging on a display rack. See also: Skin Packaging.

Blocking: The undesired adhesion of two or more plies of material to the extent that surfaces become damaged or distorted, or the inks or coatings transfer from one surface to the other when adjacent layers are separated. A condition in which two layers of film adhere to one another.

Blocking & Anticaking Agents: These additives are used to prevent the adhesion and agglomeration of ingredients within a resin compound.

Bloom (also know as Migration): An undesirable cloudy effect or whitish powdery deposit on the surface of a plastic article (or to the surrounding environment) caused by the exudation of an ingredient such as a lubricant, stabilizer pigment, plasticizer, or other non-bonded component.

Blooming: The time period that the Poly Isobutylene takes to migrate to the surface of the stretch film. Once this happens high cling films are at their peak of perfection.

Blow and Blow Process: A method of glass container manufacturing of narrow finish containers in which the parison is formed by compressed air.

Blowing & Foaming Agents: Additives for plastics or rubbers that generate inert gases within the resin matrix when heated. The resulting particle construction will have a cellular structure.

Blow Molding: Method of fabrication in which a warm plastic tube is placed between two halves of a mold cavity and forced to assume the shape of that mold cavity by use of internal pressure. This process forms hollow articles such as bottles, tanks, etc.

Blown Films: Plastic films produced from synthetic resins (such as polyethylene) by the blown process. In this process, the molten resin is extruded through a circular die into a tube. This tube is expanded (blown) by internal air pressure into a larger bubble with a much reduced wall thickness and cooled with external air quenching.

Blown Glass: Containers manufactured from molten glass that are formed by air pressure, in molds, similar in fashion to plastic molding. The finished containers are ejected or extracted from the mold, then annealed (heated and cooled) to temper the glass.

Blow Pin: Part of the tooling used to form hollow objects or containers by the blow molding process. It is a tubular tool through which air pressure is introduced into the parison to create the air pressure necessary to form the parison into the shape of the mold. On some blow molding systems, it is a part of, or an extension of, the core pin.

Blushing: The tendency of a plastic article to turn white or chalky in areas that are highly stressed.

Board: A heavy weight sheet of paper or other fiber substance (from 0.012 to 0.030 inches and up).

Body: 1) Principal part of a container, usually the largest part in one piece containing the sides.

  • In fibre drums, the body includes the sidewall and bottom bead. In certain types of drums the bottom may be formed by a continuation of the sidewall material.

  • In metal cans or drums, the cylindrical portion of the container before the end is affixed.

  • In collapsible tubes, the body (or wall) is the cylindrical portion below the shoulder extending to the bottom or crimped end.

2) In ink-making, a term referring to the viscosity, or the fluid consistency, of an ink.

Body Type:  A type used for the main part or text of a printed piece, as distinguished from the heading.

Bogus: Papers and paperboards which are manufactured from inferior materials in imitation of higher quality grades.

Boldface Type: A name given to type that has a heavier stroke than the text type with which it is used.

Bologna Slicing: A film slitting process in which a rotating double edge blade cuts a roll of film while the roll is spinning. This is the quickest way for slitting film. However, the quickness can cause the film to melt in some places, resulting in the film hanging up and tearing as it is unwound off the roll.

BON: Bi-axially Oriented Nylon film, with excellent oxygen and aroma barrier properties, (see Nylon), but it is a poor water vapour barrier. BON is much stiffer than cast nylon film, but cannot be thermoformed.

Bond Strength: A measure of strength of a bond between two adhesives.

BOPP: Biaxially oriented polypropylene

Borosilicate Glass: A high silicate glass with at least 5% boron oxide.

Boss: A raised feature of a molded part designed to add strength, facilitate alignment during assembly or for attachment to another part.

Boston Round: A style of bottle characterized by a round cylindrical shape with a short curved shoulder. Typically used by the drug and chemical industries.

Bottle: A container having a round neck of smaller diameter than the body and an opening (finish) capable of holding a closure. The cross section may be round, oval, square or other shape. The raw material may be glass, plastics, ceramics, earthenware, etc.

Bottom Drive: A machine that drives a package by means of motorized bottom belts

Bottom Liner: The surface of the boxboard which forms the interior of the carton, also called the “back-liner.”

Bottom Plate: The part of the mold which contains the heel (base) radius and the “push up” of the container to be formed.

Bottom Seal Bags: Individually cut bags from seamless tubing, sealed on the bottom. Flat or side gusseted bags with a strong seal – usually have a tail. Custom Bottom Seal Poly Bag

Box: 1) A term describing unit container made from (a) non-bending grades of paperboard, i.e., set-up box; or (b) shipping container containerboard grades of corrugated or solid fiber, i.e., corrugated or solid fiber boxes. 2) The term used to distinguish set-up, corrugated or solid fiber unit containers from cartons made from bending grades of paperboard.

Boxboard: A paperboard used in the manufacture of light non-corrugated containers. It can be plain, lined or clay-coated.

Box Compression Test: A strength test measuring the maximum load a box can withstand before collapsing.

Box Enamel Paper: A glossy coated paper used to cover boxes.

Box Manufacturer’s Certificate (BMC): A statement printed within a bordered shape on a corrugated or solid fiberboard box that identifies the manufacturer and guarantees that all applicable construction requirements of carrier classifications have been fulfilled.

Box Style: Design of a box; does not indicate size.

Braking Tension: The tension applied to stretch film, either mechanically or manually.

Branching: The modification of the molecular structure of a polymer, derived from the growth of a new polymer chain from an active site on an established chain, in a direction different from that of the original chain.

Breakdown Voltage: The voltage required, under specific conditions, to cause failure of an insulation material.

Break for Color: Also known as a color break.  In artwork and composition, to separate mechanically or by software the parts to be printed in different colors.

Breaking Strength:  A measure of the strength of paper, films, etc.

Break-out (Blade edge):  In gravure and flexography, a piece of doctor blade material which releases itself from the blade, causing a streak.

Break Pack: Transit container (e.g. large corrugated case). Also known as tertiary packaging.

Bright Can: Unprinted can prior to decoration or intended for labelling.

Brighteners: Used to add smoother or brighter coatings or finishes.

Brightness: The quality of white intensity as measured by the percent of reflectance of a boxboard surface compared to a standard block of magnesium oxide by means of an optical instrument and expressed in “points of brightness.” The recognized test procedure is TAPPI Standard T 452m. (See Whiteness)

Brittle Temperature: A measure for judging the relative merits of materials for low temperature flexing or impact; i.e., the temperature at which materials rupture by impact under specified conditions.

Broken Finish: A finish defect. A finish which has cracks or actual pieces of glass broken out of it.

Broken Mold Marks: Surface defects caused by mold damage.

Broken Ware: A general defect. Ware which is cracked or broken into pieces.

Bruce Box: A designation for a wire bound container.

Bruise Check: An edge or side defect in glass. Fine and shallow check which appears on the side or edge of the ware.

Brush Finish: A finish produced by running dried clay coated boxboard against rapidly revolving cylindrical brushes.

Brush Marks: A general defect in glass. Fine vertical laps in the side or neck of a container.

B-stage: This describes an intermediate stage of a thermoset resin reaction, where the material will soften when heated and swell in the presence of certain liquids, but may not completely fuse or dissolve. The resin is usually supplied in this uncured state.

Bubbles: Air or gas pockets that have formed in the material of the component. Bubbles may vary in size.

Buffers: Hold the packages in place before they are to enter the next section of the packaging line

Built-up: Multiple layers of corrugated board glued together to form a pad of desired thickness, normally used for interior packing.

Bulged Finish: A finish defect in glass. A finish which is blown out of shape. Bulk: Bulk is a paperboard property closely related to stiffness. It is calculated as the paperboard thickness in relation to its grammage. Graphic paperboard offers higher stiffness at lower grammage than paper—you achieve the same stiffness at about 25% lower grammage.

Bulk Density: A measurement of mass per unit volume of materials (such as powders) that describes the effects of the particle packing density.

Bulk Factor: The ratio of the volume of any given mass of loose plastic material to the volume of the same mass of the material after molding.

Bulkheading: A shipping technique that combines both unitization and stabilization. The pallet loads nearest the back door of a truck are unitized while the pallet loads towards the front of the trailer are stabilized.

Bulk-Molding Compounds (BMC): Bulk-molding compounds are used as a premix in composite manufacturing. A BMC consists of a mixture of resin, reinforcements, inert fillers, and other additives which form a puttylike preformed shape, rope or sheet.

Bulk Packaging: Unpackaged goods within a shipping container. Also, a large box used to contain a volume of product.

Buna-N: A synthetic rubber made from butadiene and acrylonitrile, used in the manufacture of flexo plates and rolls.  Resistant to aliphatic hydrocarbons, alcohols, cellosolve, and water.  Not resistant to aromatic hydrocarbons and esters (acetate), etc.

Bundle: 1) The unit of boxboard containing sheets weighing 50 pounds. The quantity of sheets varies with their size, weight and caliper; but the weight of 50 pounds per bundle is fixed. 2) Bundle also refers to a quantity of finished cartons.

Bundling: Banding articles together into distinct and separate units with plastic stretch film.

Bung: A plug used to close a barrel or drum bung hole. Called a plug when referring to a steel drum closure.

Burn: In plate making, a common term used for a plate exposure. Exposing a printing plate to high intensity light or placing an image on a printing plate by light. Burning a negative or burning a printing plate.

Burned: Showing evidence of excessive heating during processing or use of a plastic, as evidenced by blistering, discoloration, distortion or destruction of the surface.

Burn Through: A temperature or condition where a film becomes cloudy or burns in the shrink tunnel.

Burr: In gravure and flexography, a wire-like sliver formed by blade wear.

Bursting Strength: Resistance of poly to rupture under pressure, as indicated in pounds per square inch on a Mullen tester.

Butt: Joining images without overlapping

Butt Fit: Printed colors that overlap one row of dots so they appear to butt.

Butt Register: Printing two or more colors that exactly meet without any provision for color overlap.

Buttress Thread: A design of thread profile (cross section) which takes the form of a right triangle or slight modification of that form. It is usually positioned so that the right angle is at the bottom of the thread cross section and adjacent to the neck of the bottle finish. The horizontal leg of the right triangle is the bearing surface for a matching cap thread. The thread sides terminate abruptly in threading, gradually tapering down to the neck finish. The buttress thread is designed to withstand maximum force in one direction only.

Butt Splice:  An end to end joining of two similar materials.  For continuity of surface, design, etc.  Often used in joining stickyback, printing plates and webs of substrate in process such as heavy papers and boards at the unwind or rewind where the thickness or the substrate prohibits use of a lap (overlap) splice.

Byte: In computers, a unit of digital information, equivalent to one character or 8 to 32 bits.


C.T. Finish (Continuous Thread Finish): An uninterrupted protruding helix on the neck of a container to accommodate a screw type closure. Designed primarily to seal container finishes with the GPI finish number designations in the 400 series.

CA: Cellulose Acetate

Cable Extrusion: Process of extruding cables for wire sheathing or coating. Various plastic materials can be used for this process, such as PVC, HDPE, depending on the application of the extruded plastic profile.

CAD: Computer Aided Design. The process of using a computer to create a design or shape for a die layout.

Caking: The collecting of dried ink upon rollers and plates.

Calcium Carbonate: A chemical compound filler and extender used in thermoplastics, commonly found in rock.

Calendar: A group or stack of rollers between which paperboard is passed under controlled conditions of speed, heat and pressure, in order to give the material thickness, coating or surface finish.

Calendar Rolls: In paper-making, a set or stack of horizontal cast-steel rolls with polished ground surfaces at the end of a paper machine. The paper is passed between the rolls to increase the smoothness and gloss of its surface.

Caliper: The measurement of thickness either in units of micrometers (microns) or units of points for paperboard. Points are expressed as thousandths of an inch (mils), such that, .050-in. equals 50 points. Caliper measurements are used as an indirect measure of manufacturing quality.

Camera Ready Art: Artwork that’s ready for the process camera that captures the dots and density of your artwork and then translates it into a negative. No matter what color you’d like your imprint to be, the type, artwork and graphic materials should be a very high black-and-white contrast.

Can, cylinder: A can whose height is larger than its diameter.

Can, flat: Height equal to or smaller than its diameter

Can, Sanitary: A metal can with fully open aperture ends, designed for thermal processing. Supplied with a double seamed-on bottom end applied by the can-maker. The cover/second end is double seamed in place by the canner after filling; the rims of both ends are gasket or compound lined to ensure hermetic sealing.

Can: A rigid container usually made from steel, tinplate and/or aluminum, generally cylindrical and of less than ten litres capacity. (2) Verb To pack a product in a can.

Canister: A rigid container, generally round or rectangular, made of paper fibre, metal, plastic or combinations thereof, designed to pack or store dry products and having a replaceable cap, cover  or sprinkler closure (see also composite can).

Cap, Lug: A closure for glass containers in which impressions in the side of the cap provide a grip when the cap is given a quarter turn, as compared to the full turn necessary with a screw cap.

Cap, Screw: A cylindrical closure that has a thread on the internal surface of the cylinder capable of engaging an external thread on the finish or neck of a container

Cap, Snap on: used for rigid containers. Sealing effected by the gasket in the top of the cap that is held to the neck or spout of the container by means of a friction fit. Made of either metal or semi rigid plastic

Capacity: The upper possible sustainable limit of packages passing a point before warehousing or shipping in a given amount of time. Sustainable refers to the ability to maintain consistent production of quality packages at a given speed.

Capacity Requirements Planning (CRP): The process of reconciling the master production schedule to the labor and machine capacities of the production departments over the planning horizon.

Capillary Action:  A phenomenon associated with surface tension and angle of contact.  That force which transfers inks and coatings from engraved cells to a contacting surface, like from an anilox roll.  Also the rise of liquids in capillary tubes and the action of blotting paper and wicks are examples of capillary action or capillarity.

CAPP or CPP: Cast PP film. Unlike OPP, it is heat sealable, but at much higher temperatures than LDPE, so it is used as a heat seal layer in retortable packaging. It is, however, not as stiff as OPP film. (PP = polypropylene)

Caps and Small Caps:  Two sizes of capital letters made in one size of type, commonly used in most roman typefaces.

Cap Seat: The ledge inside the mouth of a bottle, such as a milk bottle, to receive a plug closure.

Carbon Tissue:  Light sensitive material attached to gravure cylinders and used as a resist in the chemical etching process. It consists of layers of gelatin, dye, photosensitive material, and a paper or plastic backing.  When exposed to a screen and a continuous tone image, carbon tissue permits the etching of cells of variable depth according to the degree of exposure in each cell area.  Until the advent of electronic engraving, this was the predominant method of imaging a cylinder.

Carboy: A bottle or similar container made of glass, plastic, metal or clay, having a capacity of 3 to 13 gallons. Where the carboy is used for shipping purposes, it is usually designed to be encased in a rigid protective outer container for shipment, often with the use of cushioning materials prescribed by DOT specifications, particularly when the carboy contains dangerous liquids. Carboys are also used for local shipment of springwater, distilled water and drinking water where no protective container is used or only a simple outer container from which the carboy is removed for dispensing purposes.

Cardboard: Generic term for any heavy pulp-based paperboard. Not a recognized term for packaging materials.

Carded Packaging: Type of packaging that consists of a stiff paperboard card onto which a product is held by a preformed plastic blister (blister card) or by a film vacuumed onto the product and card (skin or counter packaging). Blister cards are usually covered with a special coating that allows the blister to be heat sealed to the card.

Carrier Board: A term referring to board, usually Kraft, used for beverage carriers. It is often specially treated to impart water resistance since beverage carriers encounter significant moisture. (See Wet  Strength)

Carton: A container made from thin paperboard that typically measures between 0.25 and 1 millimeter in thickness. Cartons are primarily used for displaying products on store shelves. They typically feature a chipboard stock that can support printing and graphics. Boxes and Corrugated Containers

Carton-Board: A paperboard that is used to make folding boxes or cartons.

Cartoner: A machine that erects and closes carton blanks or folded and side-seam sealed cartons.

Case: A container made out of corrugated cardboard that is 3 to 6 millimeters thick.

Case Coder: Any inkjet printer that prints directly onto a package

Case Erector: Applies tape to the top of a package to seal it

Case Packer: A machine that is similar to a cartoner, but it typically works with a heavier type of paperboard.

Case Packer (Caser): A packaging machine which forms a corrugated box, and inserts the product into it. The box is subsequently sealed on a case sealer.

Cast Film: The fabrication of a film by continuously pumping the polymer through a straight slot die, then chilling the hot plastic immediately through contacts with a chilled roll. Film width is determined by how fast the chill roll pulls the film away from the die.

Casting: The process of forming solid or hollow articles from fluid plastic mixtures or resins by pouring or injecting the fluid into a mold or against a substrate with little or no pressure, followed by solidification and removal of the formed object.

Cavity: A depression, or a set of matching depressions, in a plastics-forming mold which forms the outer surfaces of the molded articles.

CCD (Charged Coupled Device): In digital prepress, a semiconductor light-sensitive electronic device that emits an electrical signal proportional to the amount of light striking it.

Cell: In printing, a small etched or engraved depression in a gravure cylinder or flexo anilox that carries the ink.

Cells per Inch (cpi): The number of cells per inch on a flexo anilox or gravure cylinder.

Cellular Plastic: Plastics containing numerous small cells, some interconnected others not, distributed throughout the mass. Used for lighter weight plastic extrusions and other PVC products.

Cellulose: See: Pulp

Cellulose Acetate Butyrate:  A clear thermoplastic material made from cellulose, reacted with both acetic and butyric acid.  Used as a packaging film and in coatings, laminations, etc.

Cellulose Fiber: Paperboard’s primary component. A carbohydrate constituent of the walls and skeletons of vegetable cells having the chemical composition of (C6H10O5)n.

Center Folder: A mechanical device used to create center-folded film.

Center-Fold Film: A film that has been folded in half, lengthwise.

Centipoise: A unit of measure of viscosity; 100 centipoise equal one poise.  Water has a viscosity of 1 centipoise (CP).

Central Impression Cylinder Press:  Printing press in which the web being printed is in continuous contact with a single large diameter impression cylinder.  The color stations are moved into the central impression cylinder for printing and are arranged around its circumference.

CEPS (Color Electronic Prepress System): In digital prepress, a high-end, computer-based system that is used to color-correct scanner images and assemble image elements into final pages.

Ceramic Labeling: A process of labeling glass containers with a label composed of colored glass that is fused to the container.

Chalking: A term that refers to improper drying of ink. Pigment dusts off because the vehicle has been absorbed too rapidly into the paper.

Changeover: the process of changing a packaging line from one product or type of package to another. It typically involves switching parts or fixtures. Changeover is an important indicator of lead time. Longer changeovers increase lead time and increase time to market; shorter changeovers reduce lead time and reduce time to market. Also called “set up.”

Changeover Time: the time it takes to exchange changeover parts for all like elements, calibrate line elements, and run the first 1000 packages or first 15 minute of production.

Charge: The amount of material used to load a mold at one time or during one cycle.

Charpy Impact Test: A destructive test of impact resistance, consisting of placing a test coupon in a horizontal position between two supports, then applying a blow of known magnitude. If the specimen does not break, a new specimen is put in position and the magnitude is increased until the specimen breaks.

Chase: A metal frame in which plates are locked for diecutting and letterpress printing.

Checked Bottom: A bottom defect. A small check that occurs on the rounded portion of the bottom near the contact surface.

Checked Finish: A finish defect. A finish which has a light, bright check in the threads or in the middle of the finish.

Chemical Durability: The resistance of glass to attack by solvents or product.

Chemical Pulp: See Bleached chemical pulp

Chipboard: A term for paperboard made from reclaimed paper stock.

Chipped Finish: A finish defect. A finish from which a small section is broken on the top or side.

Chlorinated Rubber: A chemical compound of chlorine and rubber latex forming a binder for Type T inks.  Commercial trade names are Parlon and Alloprene

Choke (choking):  When trapping color closing the open spaces in a graphic to be filled with another color. Alt:  Overlap of overprinting images to avoid color, white fringes, or borders around image detail. Called trapping in digital imaging systems.

Choked Neck: A narrowed or constricted opening in the neck of a container.

Chopped Strand: A type of fiber reinforcement consisting of strands of individual glass fibers which have been chopped into short pieces.

Chromalin: Brand name for a laminated high-quality color proof. Another popular brand is called a Matchprint. To make a Chromalin, the same color separation film negatives used to make print plates are used to apply each of the four-color process colors to four sheets (one for each color) of clear plastic. The four sheets are then fused together in exact register and laminated, resulting in an extremely accurate representation of the desired image. press proofs of Chromalins, Matchprints, or other brand name color proofs are requested by magazines along with advertisement art to evaluate printed output for color quality.

Chrome-plate: Light gauge, low carbon, cold reduced steel plate for cans, on which chromium and oxides have been electrolytically deposited.

CIJ: Continuous inkjet printer

Clamp: The part of an injection molding machine incorporating the platens that provides the force necessary to hold the mold closed during injection of the molten resin and open the mold to eject the molded part.

Clamping Area: The largest rated molding area an injection press can hold closed under full molding pressure.

Clamping Force: The force applied to the mold to keep it closed, in opposition to the fluid pressure of the compressed molding material within the mold cavity and the runner system.

Clamping Plate: A plate fitted to a mold and used to fasten the mold to a platen.

Clamping Pressure: The pressure applied to the mold to keep it closed during the molding cycle.

Clarifiers: Additive used in resins to improve transparency or translucency.

Clarity: Freedom of haze or cloudiness in a glass or plastic material.

Clay Coated Kraft Back (CCKB): Also referred to as Coated Unbleached Kraft (CUK), Coated Natural Kraft (CNK), Solid Unbleached Board (SUB), Solid Unbleached Sulfate (SUS) – Recycled paperboard that is brown on one side and clay coated on the other.

Clean Edges and Surfaces: Clean edges and surfaces promote good print quality, printability and runnability. A paperboard with edges and surfaces free from dust and fibrous debris is a prime consideration when assessing a material for optimal process efficiency, with low down-time and no unnecessary material waste. Once debris has built up on the printing press, there is no alternative but to shut it down to clean plates and blankets.

Clean In Place (CIP): A machine’s ability to be cleaned and sanitized in place on the packaging line without having to dismantle any components.    

Clinch: (1) After nailing, to bend or turn over the protruding points so that nails will hold fast. (2) To bend or crimp a metal component about anoth­er part so as to fasten the two together. For example, a can end may be loosely fastened to the can body by clinching the flange of the end under the flange of the can. The end remains loose, however, to permit air in the headspace to be removed during subsequent op­erations.

Cling: The characteristic of stretch film which makes it stick to itself. Plastic Stretch Film and Wrap

Closed-Loop Control: System for monitoring and automatically adjusting injection molding process conditions, such as temperature, pressure and time. The automatic changes keep part production within preset tolerances.

Closing Machine: A device that seals or closes filled packages by crimping, folding or tucking. Adhesives, gummed tape and ultrasonic welding are often used, in addition to heat sealing.

Closure: A sealing or covering device affixed to or on a container for the purpose of retaining the contents or preventing contamination.

CMY (Cyan, Magenta, Yellow): Subtractive primary colors, each of which is a combination of two additive primary colors (RGB).

CMYK Printing: (C – Cyan, M – Magenta, Y – Yellow, K – Black) The acronym for the four process color inks. Different combinations and amounts of the 4 ink colors are used to achieve a photographic like effect.

Coated Recycled Board (CRB): Also referred to as Clay Coated News (CCN), Clay Coated News Back (CCNB), Duplex, White Line Chip (WLC), Greyback (GB) – A high grade bending boxboard that is made using high quality recycled newspaper, except one side of the board is coated with a fine white clay for printability. CCNB is used when the light gray appearance of the backside of the board is not important.

Coated Unbleached Kraft (CUK): A grade of paperboard made entirely of virgin, unbleached pulp using the chemical papermaking process. Usually made on a fourdrinier machine.

Coating: A covering or a layer of a substance which has been deposited on the surface of a material while in fluid form, and which then hardens and bonds with the surface. In the case of paperboard, white-pigmented coating is applied on the paperboard surface (on one or both sides) in liquid form, then blade smoothed and dried. This coating provides a surface suitable for printing and varnishing, and facilitates whiteness, smoothness, and uniform absorption and drying properties. Coatings can also be applied over a printed surface in the form of an emulsion, varnish, or lacquer to protect it.

Coating Weight: The amount of coating material applied to a base material usually measured in grams/square meter.

Cobwebbing: A filmy, web-like build-up of dried ink or clear material on the doctor blade, or on the ends of impression rolls.

Coding: (1) The assignment of numerical, alphabetical or symbolic identifying marks to containers, packaging material or articles to provide information concerning the qualities of the container or of the contents, or date, plant or line in which manufactured. (2) The application of codes to a package by hand or mechanical embossing, printing, stamping, tagging or labeling.

Coefficient of Friction (C.O.F.): The amount of slip exhibited when one surface is dragged against an adjacent surface. Static COF is the force required to begin the structure moving. Kinetic COF is the force required to maintain structure movement at the test pull speed. Hi Slip = less than 0.2, Medium Slip = .2 – .5, Low Slip = more than 0.5 (kinetic) Commonly referred to as the “slipperiness” of plastic films and laminates.

Coefficient of Thermal Expansion (CTE): The change in length of a material for a unit change in temperature, per unit of length.

Coextrusion: The process of combining two or more layers of plastic extrusions to produce a multiple layer product in a single step using one tool. A co-extrusion requires compatible PVC materials that will bond together to form a strong finished part. It can be either a dual hardness (rigid/flexible PVC) co-extrusion or a two-color co-extrusion where two colors are extruded together.

Coffee Valve: A pressure relief valve added to coffee pouches to allow natural unwanted gasses to be vented while maintaining the freshness of the coffee. Also called an aroma valve as it allows you to smell the product through the valve.

Cohesion: That form of attraction by which the particles of a body are united throughout its mass.

Co-Injection: Simultaneous, or near simultaneous, injection of multiple materials.

Coke: A fuel with few impurities and a high carbon content, usually made from coal and used in steel production as fuel.

Cold Color: A color with a bluish cast.

Cold Flex (CF): Ability of a film to perform at low temperatures without failure.

Cold Flow Lines: Imperfections within the wall due to thickening or solidification of resin prior to full cavity fill.

Cold Molding: The process of compression molding involving shaping an unheated compound in a mold under pressure then heating the article to cure it.

Cold Slip: The amount of force required to slide two surfaces against one another at ambient temperature.

Collapsible Tube: A cylindrical container with an integral shoulder and neck, provided with an opening and fitted with a closure, usually a screw cap. The tube may be made of metal, plastics or combinations thereof.

Colorant (also know as Color Concentrate, Pigment): A plastic compound which contains a high percentage of pigment, to be blended in appropriate amounts with the base resin so that the correct final color is achieved.

Color Balance: The correct combination of cyan, magenta, and yellow to (1) reproduce a photograph without a color cast, (2) produce a neutral gray, or (3) reproduce the colors in the original scene or object.

Color Control: Measurements taken during the printing operation to insure that the inks match the approved progressive color proofs or other color standards for a carton; and to maintain uniformity of ink film thickness and color value during the production run.

Color Correction: Any method such as masking, dot-etching, re-etching, and scanning, used to improve color.

Colored Boxboards: Any grade of boxboard colored during manufacture by the addition of pigments or dyes to the liner pulp in the beaters.

Color Fastness: The measurement of the permanence of a color in its resistance to sunlight and various chemicals.

Color Gamut: The color gamut is the number of colors that can be reproduced with a certain color system relative to the substrate, printing method, and printing ink used. High color gamut means excellent reproduction in true colors of e.g. photographic images, and is enhanced by a very smooth and uniform paperboard surface

Colorimeter: An instrument for measuring color the way the eye sees it.

Color Key: An overlay proof created from the film separations that places each ink color on a separate, clear acetate sheet, then assembles them together over white paper. Color Key is actually a brand name for a specific process that is often used generically to apply to any overlay proofing system.

Color Management: A system of hardware, software, and procedures that are calibrated to best ensure color accuracy and repeatability throughout the design and production process.

Color Matching System: A system of formulated ink colors used for communicating color. Pantone Matching System is a very common universal system used for this.

Color Overlap: The slight extension of one color over another.

Color Overlay: A transparent overlay, usually acetate, on a Black & White drawing on which each additional color is indicated as a guide for reproduction.  A term sometimes used at press side referring to the number of colors that overprint each other.

Color Process: Halftone color printing created by the color separation process whereby a piece of copy is broken down to the primary colors to produce individual halftones and these are recombined at the press to produce the complete range of colors of the original.

Color Proofs: See off-press proofs, progressive proofs.

Color Separation: The translation of an original photograph or other artwork into separate plates for four-color printing.

Color Stations:  Each section of the press, or the set of rollers used to print each individual color.

Color Transparency: A full-color photographic positive image on a transparent support.  Usually viewed with the aid of a lighted color transparency viewer.

Colorway: A specific combination of colors in the pattern of a transfer printed design.

Column Crush: A test performed on a small sample of corrugated board which is a measure of the compression strength of that sample. Also referred to as edge crush and short column crush.

Combination Plate:  A single engraving that includes both line and halftone.

Combined Board: A fabricated sheet made from multiple components, such as solid fiberboard or corrugated.

Commercial Register:  Color printing on which the misregister allowable is within one row of dots.

Common Impression Cylinder Press: In flexography, letterpress, lithography, and digital printing, a press with a number of printing units around a large impression cylinder.

Compatibility: Ability of a container, whether lined or unlined, to resist degradation of or by the product contained.

Complementary Colors: A pair of contrasting colors that produce a hue neutral in color and value when mixed in suitable proportions.

Components: Input items or product items. Ex: labels, seals, containers

Composing Stick: A unit used to hold each individual character of type that is needed.  The type can be locked into position until the proofs are pulled or a cast is made.

Composite Can: A rigid container with the body made of paper fibre or a combination of fiberboard and other materials such as aluminum foil or plastic films. The ends may be made of metal, plastic or other materials.

Composite Film: Combining two or more images on one or more pieces of film.

Compound: (1) Substance containing two or more chemically combined ingredients in its composition. If not chemically com­bined it is said to be a mixture. (2) Combination or mixture of  materials, such as plastics polymers. For example, can sealing compounds are emulsions or solutions of rubber or plastics used to achieve hermetic seals between the can body and ends.

Compressibility: The behavior of paper under pressure, such as that applied by the gravure impression roller.  A function of basis weight and caliper.  No separate test for compressibility exists, but is evaluated during tests for smoothness.

Compression Molding: A method of molding in which the molding material, generally preheated, is placed in an open heated mold cavity. The mold is closed with a top force and pressure is applied to force the material into contact with all mold areas.  

Compression Set: The extent to which distortion of rubber (expressed as percentage of the original thickness) has become permanent, after subjecting a test piece to a known load between plates for a specified time.

Compression strength: 1) Paperboard: Compression strength is the paperboard’s ability to resist compression forces. Multi-ply paperboard has a unique relationship between compression strength and tensile strength–the compression strength is always two to three times lower than the tensile strength. This relationship is a key factor for permitting creasing, folding, and embossing/debossing. 2) Corrugated: A corrugated box’s resistance to uniformly exerted external forces. Measured by the compressive resistance of a container determined by an edge crush test. See also: Edge Crush Test

Compression Zone: Also called the transition or melting zone, it’s a zone in the extruder screw barrel. Most of the plastic compound is melted in this section, and the channel depth gets progressively smaller.

Computer, Analog: A computer that solves a mathematical problem by using analogs, like voltage or density, of the variables in the problem.

Computer, Digital: A computer that processes information in discrete digital form.

Computer-aided Manufacturing (CAM): The use of a computer and postprocessing or linking software to manipulate and compile data into a machine language for a machine to execute the desired function.

Computer-to-Plate: An entirely digital workflow used to design and transfer graphics and copy to the printing plate output device (plate setter) without the use of films.

Condensed Type: A narrow or slender typeface.

Conditioning: Subjecting a material to standard environmental and/or a non-standard stress state prior to testing or use.

Conductivity: An electrical property of fountain solutions that must be controlled along with pH.

Consistency: Property of a material that is evidenced by its resistance to flow.  The general body characteristics of an ink, for example, viscosity, uniformity.  Mostly used to describe the rheological property of an ink – such as “thick”, “thin”, “buttery”.

Constant Gloss Test: A paper test for gloss used on matte or uncoated papers, used to determine if undesirable reflections will hamper readability of the printed sheet under normal viewing conditions.

Constant Pressure Gradient: Pressure drop per unit length. The constant pressure gradient principle says that the most efficient filling pattern is when the pressure gradient is constant along the flow path.

Contact Angle: Actual wiping angle of doctor blade on cylinder.  Resultant of forces at work in the particular application.

Contact Area: Area of doctor blade in actual contact with print cylinder when wiping.

Contact Positive: A positive made from a negative by exposure to light in a contact frame, either continuous tone or screened.

Contact Print: A photographic print made from a negative or positive in contact with sensitized paper, film or printing plate.

Contact Screen: A halftone screen on film. Has a dot structure of graded density, used in vacuum contact with the photographic film to produce halftones.

Container: Any containing vessel used in packaging for distribution or shipping. Freight containers: a relatively large reusable structure to be filled with smaller objects to facilitate their distribution.

Containerboard: A general term applied to both solid fiberboard and corrugated fiberboard which are used in the manufacture of shipping containers. Containerboard grades include medium and linerboard.

Continuous Motion: Package line moves in a steady motion without pause

Continuous Service Temperature: The highest temperature at which a material can perform reliably in long term application. Defined by the manufacturer.

Continuous Thread: An uninterrupted protruding helix on the neck of a container to hold a screw-type closure.

Continuous Tone: An image that contains gradient tones from black to white.

Contone: Abbreviation for continuous tone.

Contour Packaging: The overwrapping or covering of an irregular-shaped object with a flexible film applied in connection with a paperboard base. The air surrounding the product is exhausted, causing the film to fit or cling closely to all parts of the packaged item. Also referred to as “Skin Packaging.”

Contract Proof: An approved color proof of the job, representing an agreement between the printer and the customer regarding how the printed product will look.

Contrast: The tonal change in color from light to dark.

Control: The ability or control to regulate, direct, or dominate a series of events. In packaging it is important to be in control of the packaging line.

Control Chart: A visual record of quality performance in a statistical process. It is a graph produced by plotting the value of each sample drawn from the process. The number of the observation should go along the horizontal axis and the value of the observation along the vertical axis.

Controlled Frictional Heating: Runners designed to deliver a higher melt temperature to the cavity. This results in lower stress levels in the part, without causing material degradation due to long exposure to elevated temperatures in the barrel.

Conversion: The process of creating a three dimensional (3D) item from a flat sheet of paper.  i.e. envelope conversion/box conversion.

Conversions (Commonly Used in Injection Molding)

KPa x 0.145 = psi

MPa x 145 = psi

°C x 1.8 + 32 = °F

Liters/min x 0.2642 = Gal/min

Inches x 25.4 = mm

Flow rate = ((# of cavities) x (volume per cavity))/(injection time)

Converter: A general term referring to any manufacturer who makes packaging materials from raw materials. For example, a manufacturer who fabricates folding cartons from boxboard and other packaging materials.

Conveyor: A track that is used to move packages/product without manual intervention

Convolute Can: A cylindrical can made by convolute winding of the materials to build up the desired thickness and resistance properties.

Cooling Channels: Channels located within the body of a mold through which a cooling medium is circulated to control the mold surface temperature.

Cooling Time: The elapsed time required for the melt to reach its Vicat softening temperature.

Copolymer: Result of two monomers being combined through polymerization.

Copy: All furnished material or disc used in the production of a printed product.

Copyfitting: In composition, the calculation of how much space a given amount of copy will take up in a given size and typeface.  Also, the adjusting of the type size to make it fit in a given amount of space.

Copy Preparation: Directions for, and checking of, desired size and other details for illustrations, and the arrangement into proper position of various parts of the page to be photographed or electronically processed for reproduction.

Copyright: A group of legal rights granted to the author or creator of written or visual work.  All work appearing with the 8 symbol or word “copyright” is protected by its creator or his heirs.  For more information contact an attorney.

Cord: Defect in glass containers. A narrow, stringy band of glass of a composition different from the rest of the glass surrounding it.

Core: A protrusion, or set of matching protrusions, in a plastics forming mold which forms the inner surfaces of the molded articles.

Core Brake: Restricts pull-off rate of a pallet wrap film

Core Holder: Device for affixing core to shaft.

Cork: A finish which is closed by means of a cork.

Corkage Check: A finish defect. A bright, light check which is not unusually deep and is located on the inside of the top of the finish.

Cornerboard: A reinforcing member designed to fit around the corner of a pallet load. It provides support for strapping and prevents damage to the corrugated boxes by the strapping, also increasing the compressive strength of the pallet board.

Corona Treatment: Impingement of AC power on a component to bombard it with free radicals, improving the ability to bond to a surface.

Corrosion: The gradual destruction of a material by another substance, like rusting. Corrosion inhibitors can be incorporated inside the package or within the packaging material (bags) itself to retard or inhibit corrosion, e.g. vapour phase inhibitors.

Corrosion Resistance: A broad term applying to the ability of plastics to resist degradation in many environments, usually die to oxidation.

Corrugated: A durable, lightweight material used for making cases. Corrugated packaging has an arched layer, called fluting, between smooth sheets, called liner. The corrugated cardboard most commonly used to make cases has one layer of fluting between two smooth sheets. Boxes and Corrugated Containers

Corrugated Board: A structure made from containerboard grades of paperboard. Corrugated consists of a medium, that has been fluted on a corrugator, to which one (single-face), two (double-face), or more sheets of linerboard are attached to create the structure. A double-face corrugated container is referred to as a single-wall container. Corrugated is primarily used for shipping containers. The height of the fluted medium varies and is referred to by a letter. Common flute sizes are A, B, C, E, F, G and N.

Corrugated Medium: Paperboard material used to form the fluted portion of a corrugated board. See also: Fluting

Corrugated Plant: A corrugated manufacturer who possess a corrugator and converting equipment and produces both sheets and boxes.

Corrugation Marks:  A paper defect having the appearance of “rope” or “chain” marks parallel to the direction of web travel, caused by adjacent hard and soft spots.

Corrugator: A machine that makes corrugated boards by joining fluting and liners.

Count: The actual quantity of sheets of a given size, weight and caliper required to make a bundle of 50 pounds.

Counterchange: To alternate tonal values within a design, e.g. from light against dark to dark against light.

Counter Plate: A component containing channels or grooves affixed to the press plate on the cutting press, which in combination with the die creasing rule, defines the fold lines of a carton.

Coupling Agents: A material that is used to form a chemical bridge between the resin and an additive, such as glass fiber or mineral fiber. By acting as an interface, bonding is enhanced.

Cover: (1) The top, end or lid of a container, usually the part which closes the filling or dispensing opening. (2) A wrapper. (3) The closure or head of a metal container or drum when not joined to the body by double seaming.

Coverage: Ink or coating mileage:  The surface area covered by a given quantity of ink or coating material.  In flexography, the extent or degree to which a base material is covered, colored, or hidden by an ink or coating.  Hiding power.

Cover paper: A heavy printing paper used to cover books, catalogs, brochures, booklets, make presentation folders, etc.

Cover Sheet: A layer of clear material that is taped or laminated over artwork or proofs to protect the surface from damage.

Crack/Splits/Chips: A physical separation or tearing of the part.

Crash: Excessive impression of plate to stock or transfer roll to plate.  Characterized by a halo effect or double outline.

Crash Finish: A paper finish with a surface similar to coarse linen.

Crash Lock (glued): A style that enables the base of the case to be locked together without the use of tape. It can also be adapted by incorporating a glued section that allows for speedy assembly.

Crash Number: Numbering paper by pressing an image on the first sheet which is transferred to all parts of the printed set.

Cratering: Small, thin or bare spots in an applied coating that have the appearance of pockmarks.

Crawling: That property of an ink film in which the wetting of the surface is too poor, preventing the film from contracting into drops, leaving a discontinuous covering.

Crazing: Defect in plastics articles characterized by distinct surface cracks or minute frost-like internal cracks, resulting from stresses within the article which exceed the tensile strength of the plastic.

Creasability: Creasability is the paperboard’s ability to permit deep and narrow creases along well defined fold lines. Since the creasing operation involves an intentional and well controlled delamination of the inner plies of the paperboard without cracking or damaging the surface plies and coatings, creasability depends on a combination of many paperboard features. Key properties are elasticity, elongation, bending moment, bending resistance, tensile strength, compression strength, delamination strength, surface strength, flatness, and dimensional stability.

Creasing: Paperboard should always be creased before it is folded. Creasing facilitates distinct, durable and narrow fold lines, with no cracks on the folds.

Creep: The deformation, in either cured or uncured rubber under stress, which occurs with lapse of time after immediate deformation. With rubber covered rolls, the metal roll body is subject to creep, as well as the rubber.  Creep can also occur when a roll is kept in storage without turning.

Creepage: The slight continuous cumulative tendency of a color to drift out of register or position, in the running direction.

Crimped Seal: A method of sealing with pressure applied by knurled wheels or bars having a serrated surface. Generally stronger than a similar seal without crimping.

Crimping: Puncture marks holding business forms together.

Crimp Seal: A seal formed with a corrugated pressure type of heat seal mechanism.  The seal has a wavy appearance.

Crizzled: Finish A finish defect. A finish which has a multitude of fine surface fractures across the top.

Crooked: Finish A finish defect. A finish which has a bent or crooked appearance. Also called “bent finish”.

Crop: To eliminate portions of the copy, usually on a photograph, indicated on the original by cropmarks.

Crop Marks: Printed lines showing where to trim a printed sheet.

Cropping: Trimming off unwanted areas of an illustration, photo, or other art work.

Cross-Deckle Misregister: Misregister caused by shrinking of a web between printing units.

Cross Direction: In paper, the direction across the grain.  Paper is weaker and more sensitive to changes in relative humidity in the cross direction than the grain direction.

Cross Hatch: Regularly crossed over parallel lines to create various effects of tones and shades.

Cross-Linking: A process which binds the polymer chains into a network. Significantly increasing a film’s heat stability and strength.

Cross Top Wrapping: A unitization technique which covers the top of a load. Not only does cross top wrapping protect the tops of pallet loads but it alsoserves to pull the load together as it settles during shipment.

Crow’s Feet: A series of wrinkles radiating out from a finished package’s corners.

Crown: The difference in diameter between the center of a roll and reference points at or near the ends of the face.

Crown (cork): A metal closure, lined with cork or plastic. The cap is crimped around its rim over the finish of a bottle to provide a hermetic seal.

Crown Finish: The neck finish on beer and beverage bottles sealed with a crown cap.

Cryogenic Processes: Reduction of parts to very low temperatures usually achieved with liquid nitrogen. Commonly used to create assemblies or to deflash or de-gate a part.

Crystal: A homogeneous solid having an orderly and repetitive three-dimensional arrangement of its atoms.

Crystallinity: A state of molecular structure in some resins attributed to the existence of solid crystals with a definite geometric form. Such structures are characterized by uniformity and compactness.

CSA: Abbreviation for the Canadian Standards Association.  

C-stage: This term describes the final stage of the reaction where a thermoset material is relatively insoluble and infusible.

CTFE: Abbreviation for the scientific name of Chlorotrifluoroethylene. The common trade name is Aclar. Is most often used as a laminated barrier film in packaging medications in blister packs.

Cube: The total area inside a truck trailer. The length times width times the height of the trailer is the cube space.

Cubic Capacity: The total volume within a container. The volume of material that may be held in a container, in terms of its internal di­mensions; does not allow for necessary outage (head-space).  An exception is made in the case of bags, for which capacities are determined by exter­nal dimensions because the material thickness is usually negligible.

Cullet: Glass, from containers not approved by selectors, that has been crushed or broken and is added to the batch to be remelted and formed into new containers; or recycled broken glass that is used in the manufacture of new glass.

Cure or Curing: 1) Conversion by chemical reaction of a wet coating or printing ink film to a solid film.  2) Also refers to the addition of a catalyst. Alt:  The step in the manufacture of a rubber roller or a rubber plate in which it is subjected to temperature elevation under pressure for a length of time to vulcanize the elastomer until it reaches its optimum in elasticity and tensile strength.  As applied to rubber rollers, the aging cycle required following vulcanization.  To treat (with heat) to make infusible.

Curl: An undesirable condition caused by uneven rates of absorption or evaporation of moisture, uneven rates of contraction or expansion, or internal stresses in the material. Curl is most prevalent in laminated structures where the components have differing physical property.

Curve Direction: Direction of web travel on a flexo press.

Custom J or Lip Poly Sheeting: One side of the plastic film is longer than the other, which allows for quick and easy separation. Very convenient for a wide range of odd products with unusual shapes or compositions.

Custom Molder: A firm specializing in the molding of items or components to the specifications of another firm which handles the sale of distribution of the item, or incorporates the custom molded components in one of its own products.

Cut: 1) The term properly applies to wood engravings and other surfaces manually engraved. It is frequently used inappropriately to mean photoengraving. 2) To pierce or shear completely through a sheet of paperboard; i.e., to cut carton blanks from a sheet of paperboard. 3.) In gravure/flexography, to dilute an ink, lacquer or varnish with solvents or with clear base; to thin.

Cut and Crease Score: An alternative to a crease score wherein the fold line is made up of a series of alternating cuts and creases.

Cut-Back: The process of reducing the size of an image so that the printed area produced by such a cut-back can be covered by an overprinting area.

Cut-Off: In web printing, the cut or print length.

Cutscore: In die-cutting, a sharp-edged knife, usually several thousandths of an inch lower than the cutting rules in a die, made to cut part way into the paper or board for folding purposes.

Cutting and Creasing Die: Steel rule forms used on cutting and creasing presses to cut and score sheets of boxboard into folding carton blanks.

Cyan: One of four standard process colors.   The color blue. Alt:  Hue of a subtractive primary and a 4-color process ink.  It reflects or transmits blue and green light and absorbs red light.

Cycle: complete, repeating sequence of operations for injection molding a part.

Cycle Rate: The rate of machine cycles per minute.

Cycle Time: The time required by an injection molding system to mold a part and return to its original position/state.

Cylinder: In flexography, for no particular reason, most rollers in the printing press are called rolls on which the rubber plates are mounted. The one which receives the impression is usually referred to as a cylinder, i.e., Plate Cylinders, Impression Cylinder.

Cylinder Board: Boxboard made on a papermaking machine characterized by the use of a series of cylinders or molds, each laying down a single layer (or ply) of fiber, which permits wide variation in the thickness or weight of the finished board as well as a variation in the furnish used in the different layers, or plies, of the sheet. There is a grain in the direction in which the web travels.

Cylinder Gap: In printing presses, the gap or space in the cylinders of a press where the mechanism for plate (or blanket), clamps, and grippers (sheetfed) is housed.

Cylinder Machine: A machine for making paper and paperboard which consists of wire cylinders revolving in vats containing furnish of different types. Each cylinder deposits a layer of furnish (paper pulp and water) on the moving web or blanket to form separate layers, the fibers of which are combined under pressure into a single sheet as the water is squeezed out. The web is built up to a desired thickness by carrying it on a belt over successive cylinders.


Dampeners: In lithography, cloth-covered parchment paper, or rubber (bare-back) rollers that distribute the dampening solution to the press plate or ink roller.

Damper: Usually a pivoted gate or valve used to control the flow of air or other gases, as in the dryer.

Damping: The effect on a mass that causes decreasing amplitude.

DCS (Desktop Color Separation): In digital prepress, a data file defined to assist in printing process color separations using desktop color systems. Using DCS, five files are created: cyan, magenta, yellow and black image data, and a composite color preview of the color image.

DDES:  Acronym for Digital Data Exchange Specifications.

Dead Fold: Stretch film sticking to itself during wrapping without the use of any additional heat sealing (i.e. – PVC films used in food wrapping have high dead fold). Plastic Stretch Film and Wrap

Deboss: An image or area pressed into paper or board creating a sunken area.

Debossing: Trade jargon for what can more precisely be described as negative embossing. Debossing may be accomplished by using 1) matched dies to form a depressed surface in the paperboard, or 2) a male die (slug) only to depress an image such as code numbers or a manufacturer’s logo into the surface of a paperboard substrate.

Debris: Debris refers to particles either of the paperboard’s origin or particles coming from the ink or press room. Debris may cause print blemishes or spots. This problem can be avoided by creating a paperboard created with clean edges and surfaces.

Deckle: The width (CD) of the paper or board being run on a corrugator.

Decompression Zone: Zone in a double screw extruder, about two-thirds down the screw, where the channel suddenly gets deeper, relieving the pressure and allowing any trapped gases (usually moisture or air) to be drawn out by vacuum.

Deep Drawing: (1) In thermoforming of plastics, the stretching of a formable web into a mould to the near limit of its elasticity. (2) In metal, forcing a piece or sheet of metal in a die press operation.

Deflashing: Any technique or method which removes excess material (flash) from a molded article, specifically from those places where parting lines of the mold may have caused the excess material to form.

Deflection Temperature: The measurement of temperature at which a specimen deflects to a set point under a defined load.

Degassing: The momentary opening and closing of a mold during the early stages of the cycle to permit the escape of air or gas from the heated compound.

Degradation: A deleterious change in the chemical structure, physical properties or appearance of a plastic caused by exposure to heat, light, oxygen, weathering or other external influence.

Delamination: Delamination is the separation of the different plies of multi-ply paperboard. In some processes, such as creasing, it is desirable to delaminate the inner plies without damaging the outer plies.

Densitometer: A reflection densitometer is used to measure and control the density of color inks on the substrate. Densitometry may be built into reproduction devices.

Density: 1) Weight per unit volume of a material expressed in g/cm3 (kg/m3). 2) In paperboard, Density is the compactness of the paperboard (i.e. the inverse of its bulk). Density is calculated as the paperboard grammage in relation to its thickness. 3) In printing, the degree of darkness (light absorption or opacity) of a photographic image.

Depressed Thread: Thread on the finish of glass containers in which the thread is reduced in depth or “depressed” at the two points where the thread crosses the mold parting line.

Descender: That part of a lowercase letter that extends below the main body, as in “p”.

Desensitizer: In platemaking, chemical treatment to make non-image areas of a plate repellent to ink.  In photography, an agent for decreasing color sensitivity of photographic emulsion to facilitate development under comparatively bright light.

Design: (1) Graphic – The surface decoration and wording printed on a package to inform, instruct and attract the customer. (2) Structural – The conception of the physical construction of the package, to produce the most effective and economical result.

Design for manufacture (DFM): A general approach to designing products that can be more effectively manufactured.

Design Review: A review of a blueprint of an application to be molded in a plastic material, with recommendations given for design, material, processing, tooling.

Design Roll: Printing cylinder with elastomeric plates affixed in position, for all-over printing.

Design Speed: The theoretical capacity obtained in a perfect operating environment. All adverse operating conditions are neglected, and all machinery is assumed to be in optimum operating condition.

Design Style: A style of fiberboard trays or caps with scored, folded, and secured flaps at the flange side walls, which forms the depth.

Desktop Publishing: A process for creating artwork on a personal computer that is rarely acceptable for professional printing. It is meant for the user to communicate to a very small limited audience, such as interoffice, and NOT for professional marketing or design pieces.

Destruct Bond: A strong bond of two materials where if one attempts to pull the two apart a destruction of one of the materials will occur. The bonding agent is stronger than the materials bonded together.

Developer: In photography, the chemical agent and process used to render photographic images visible after exposure to light.  In lithographic platemaking, the material used to remove the unexposed coating.

Dial Indicator: A watch-like instrument used to measure concentricity, run-on, deflection, and relative position of mechanical components.

Diaphragm Gate: Used in symmetrical cavity filling to reduce weld-line formations and improve filling rates.

Diatomaceous Earth: A substance consisting of the skeletons of billions of microscopic plankton, containing a high amount of silicon.  A common paper filler, also used in ceramics, glazes, dynamite and pest control.

Diazo: A light sensitive coating used on printing plates.

Die: A device used in extrusion processes to shape the extrudate. Metal rule or imaged block used to cut or place an image on paper in the finishing process. Alt: Any of various sharp cutting forms, rotary or flat, used to cut desired shapes from paper, paperboard or other stocks.  Also a carry-over term for printing plates in flexo industries previously letterpress which in early years used metal printing plates, i.e., corrugated, publications, etc.

Die-Cut: A box that is stamped out from a steel rule die, as opposed to being produced on a flexo folder gluer. Die-cut boxes provide greater design options and tighter size tolerances.

Die-Cutting: Cutting images in or out of paper. Alt:  The process of using sharp steel rules to cut special shapes for labels, boxes and containers, from printed sheets.  Die-cutting can be done on either flatbed or rotary presses.  Rotary die-cutting is usually done in-line with the printing.

Dielectric Strength: The voltage that an insulating material can withstand before dielectric breakdown occurs.

Die-line: A detailed line drawing showing the plan view of the design and style of the carton or container before erection. Can also be called a cutter guide.

Die Sheet: An accurate imprint or transfer made on vinyl or oiled sheet from the die form so that the print image can be brought into exact register with the cutting and creasing rules. Also called a “strike” sheet.

Die-stamping: The intaglio process of reproducing a design, figures or lettering from engraved plates of copper, steel or other metal, usually on a die-stamping press.

Differential Cooling: Occurs when one area of the part cools at a different rate or when the mold surfaces are at different temperatures. Warping can result from differential cooling.

Diffusion: A spreading out or equalized dispersion of a material, force, or condition into the surrounding medium: the diffusion of heat by conduction; the diffusion of light through a translucent material or reflection from a rough surface; the diffusion of gases, liquids or granular solids into the surrounding medium.

Diffusion Transfer: In photography and platemaking, a system consisting of a photographic emulsion on which a negative is produced, and a receiver sheet on which a positive of the image is transferred during processing.

Digital Color Proof: An off-press color proof produced from digital data without the need for separation films.

Digital Imaging: The process of creating a digital copy of an illustrated or photographic image.

Digital Photography: The process of recording images using a digital camera or a conventional camera with a digital adapter.

Digital Plates: Printing plates imaged using lasers or other high-energy sources driven by digital data in a platesetter.

Digital Printing: A system of printing, which involves linking state-of-the-art printing presses and computers, bypassing the traditional route of making printing plates. Alt:  Printing by plateless imaging systems that are imaged by digital data from prepress systems.

Digital Screen Halftone: In color separation, a halftone negative is made by direct exposure from the original on an enlarger or by contact through a halftone screen.

Digitized Typesetting: In typographic imaging, the creation of typographic characters and symbols by the arrangement of black-and-white spots called pixels or pels.

Digitizer: A computer peripheral device that converts an analog signal (images or sound) into a digital signal.

Dilatant: Having the property of increasing in viscosity with increase in shear.  Dilatant fluids are solid or highly viscous when stirred, and fluid when undisturbed.  The condition can occur in flexo inks but is normally considered highly undesirable and one to be avoided through formulation.

Diluent:  A liquid having no solvent power by itself, used to thin an ink; not having a solvent action.

Dimension “C”: The “C” dimension of a bottle is the opening control diameter (inside

Dimension “E”: The outside diameter of the neck. The difference between the “E” and “T” dimensions divided by two determines the thread depth.

Dimension “H”: BOTTLE “H” Dimension: The height of the neck finish. Measured from the top of the neck to the point where the diameter “T”, extended down, intersects the shoulder. The bottle finish “H” must be greater than closure “H” (corrected for the thickness of the compressed liner or other sealing elements). CLOSURE “H”: The “H” dimension is measured from the inside top of the closure vertically down to the bottom of the closure skirt. Effective “H” must take into consideration the liner, or other sealing element, if one is used. To determine effective “H”, liner thickness or other sealing element under compression must be determined and subtracted from unlined “H”.

Dimension “I”: The minimum opening through the finish and neck expressed by measuring the inner diameter of the neck at its narrowest point. Specifications require a minimum “I” to allow sufficient clearance for filling tubes. Linerless closures, with a plug or land seal, and dispensing plugs and fitments require a controlled “I” dimension for proper fit.

Dimension “L”: L dimension is the minimum vertical dimension to the top of a concealed bead for closure thread clearance. It is measured from the top of the finish to the point where diameter “E” extended parallel to centerline intersects the bead.

Dimension “S”: Measured from the top of the finish to the top edge of the first thread. The “S” dimension is the key factor which determines the orientation of the closure to the bottle and the amount of thread engagement between the bottle and cap.

Dimension “T”: The outside diameter of the closure, including the thread. The tolerance range of the “T” dimension determines the mate between the bottle and the closure.

Dimensional Stability and fFatness: Dimensional stability is the paperboard’s ability to resist dimensional changes due to moisture changes. Flatness is the paperboard’s ability to remain flat after the printing and finishing operations. Both are crucial properties, since any change to the sheet shape and dimensions affects the runnability of the printing, the finishing processes and the quality of the finished graphic product.

  • Since paperboard is a hygroscopic material, it will change its moisture content when exposed to changing humidity. When the two surfaces of the sheet are equal in terms of their capacity for moisture expansion, the paperboard is as close to the ideal symmetric sheet as possible. However, in practice almost all paperboard products are more or less asymmetric. Therefore the paperboard is manufactured to meet an ideal shape at a predetermined level of moisture content (50% relative humidity).

  • The choice and composition of raw materials and firmly controlled manufacturing processes are crucial for producing a paperboard that retains its dimensional stability and flatness throughout all operations. It is therefore important to keep the relative humidity of the surroundings very close to the 50% level before, after, and during the printing and finishing operations.

Dimensions: For a regular slotted containers (RSC), box dimensions are expressed as Length x Width x Height, always using inside dimensions.

Direct Gate: A sprue that feeds directly into the mold cavity.

Direct Imaging: A process replacing off-press plate-making employing a laser imaging head to create printing plates on press.

Direct Labor: considered “touch” labor since employees physically touch the product or inputs

Direct Screen Halftone: In color separation, a halftone negative made by direct exposure from the original on an enlarger or by contact through a halftone screen.

Direct-to-Plate: See CtP

Dirty Finish: A finish defect. A finish which has a scaly appearance and which may even have black spots in it. Dirty Neck A neck defect. A neck which has a dirty or scaly appearance.

Dirty Ware: A general defect. Ware which has carbonaceous or dirty deposits on it.

Discoloration: Any change from the designated color of the material or component.

Dispersing Agents: Materials added in small amounts to facilitate dispersion of a pigment into a liquid medium; also, wetting agents.  (Ink Additive)

Display: A folding carton style designed to provide a point-of-purchase unit for holding a number of individual packages or products.

Display Type: In composition, type set larger than the text.

Disposable Package: A package specifically designed for a single use and not to be refilled.

Distorted: Intentionally compensating of solid particles in a vehicle by mixing or milling.

Distortion Copy: Copy which is intentionally distorted in preparation, in order to compensate for the effects of dimensional changes due to subsequent processing or operation.  Flexographic printing requires such allowances to compensate for shrinkage, stretch, etc.

Distortion Plate: Plates made from distortion copy.

Distortion Print: Distorted printing of a design on flat metal or plastic surfaces that are subsequently deformed or stretched, so that it appears correct after deformation has taken place.

Distribution Packaging: Refers to integrated package and product handling from factory to point of sale. It is usually understood that distribution packaging means the outer and/or intermediate container which is required for efficient transportation and storage.

Dithering: A technique for alternating the values of adjacent dots or pixels to create the effect of intermediate values. It is a substitute for halftone or contone reproduction.

Doctor Blade: 1) The part of an inking system on a gravure or flexographic press which scrapes off or removes surplus ink from the printing cylinder before the image is transferred to the sheet or web of board or paper. 2) Also used on other machines to remove excess amounts of coatings, adhesives or other materials being applied to boxboard sheets.

Doctor Blade Holder: Upper and lower clamp supports for doctor and back-up blades. Gravure/Flexography

Doctor Blade Loading: Applying doctor blade pressure against the engraved cylinder. Gravure/flexography

Doctor Roll: The fountain roll in a flexographic press.

DOD: (Drop On Demand) inkjet coding with limited print capability

Dog-Ears: Triangular projections of film at the corners of finished packages that has not been properly shrunk.

Dominant Flow Path: At the juncture of two confronting flows, the dominant flow will reverse the direction of the other.

Doorknob Bags: Side-weld bag, staple-packed with perforated lip and hole just below the top of the bag. Custom Door Knob Hanger Bags

DOS (Disk Operating System): In digital printing, a program containing instructions for a computer to read and write data to and from a disk.

Dot: Smallest digital imaging or screening element. A halftone dot is composed of many spots. The fineness of a halftone screen is measured in “lines per inch” or lpi. Dots per inch (dpi) is a measure of image quality. In AM screening the dots vary in size; in FM screening all the dots are the same size.

Dot Etching: In photography, chemically reducing halftone dots to vary the amount of color to be printed.  Dot etching on negatives increases color; dot etching on positives reduces color.

Dot Gain or Spread: A term used to explain the difference in size between the dot on film versus on paper. Alt:  A phenomenon, which occurs when wet ink comes in contact with paper.  As the halftone dots are applied to the paper, the wet ink spreads, causing the dots to increase in size and halftones to appear darker.  A number of factors affect dot gain.

Dot Growth: The enlargement of a halftone dot from the printing plate to the printed image as a result of pressure needed to transfer the ink onto the substrate.

Dot Matrix: Style of printing that uses a microjet or valve technology case inkjet printer. Ex. 5×3 means 5 dots high and 3 dots wide

Dots Per Inch (DPI): A measure of the resolution of a screen image or printed page.

Double Burn: Exposing a plate to multiple images.

Double Seam: A joint attaching the top or bottom end of a metal can to its body, formed by interlocking the edges of the end and the flanged body, double folding and rolling firmly together.

Double Stacking: One pallet placed on top of another during shipping.

Double Wall: A corrugated board consisting of two layers of medium that are glued between three layers of flat linerboard facing.

Doughnut: The appearance of a screen dot that has printed the circumference of the cell while not printing a complete dot.

Down Finish: A finish defect. A finish which is incompletely filled.

Downtime: The amount of time a machine or system is not functioning due to stoppages in a given shift or time period.

Downtime Analysis: A production process tool that tracks the amount of time a given machine or system ceases production.

Doy Pack (Doyen): A stand-up pouch that has seals on both sides and around the bottom gusset. In 1962, Louis Doyen invented and patented the first soft sack with an inflated bottom called Doy Pack®. Although this new packaging was not the immediate success hoped for, it is booming today since the patent has entered the public domain.

Draft: A Slight taper in a mold wall designed to facilitate removal of the molded object from the mold.

Drag Marks: A form of deep scratch or scratches on the surface of the component usually caused by the ejection of the part.

Drape: The softness of a film characterized by its ability to conform to irregular shapes.

Draw Down: A thin coating applied and spread by a number of instruments, hand rollers or pulling a smooth flat knife blade. Used to check such coating characteristics as shade, color strength and tones.

Drawn and Ironed Can (D&I): After the can has been drawn (see also: Drawn Container) to form its basic shape, the sides are thinned by ironing further.Drawn and Redrawn Can (DRD): Steel or aluminium two-piece cans with thicker walls than D&I cans (see above), suitable for retorting. Relatively shallower than D&I cans.Drawn Container: A container made by forcing a flat metal or plastic blank or sheet into, through or over a die.

Drier: A substance added to ink and other material to accelerate its rate of drying.

Drift: 1) The continued deformation of rubber under strain. 2) The change in a given durometer reading after a specified period of time.

Driving Side: The side of a flexographic press on which the main gear train(s) are located; also gear side; opposite of operating side.

Drooling: The extrudation or leakage of molten resin from the nozzle or nozzle sprue bushing area while filling or shooting the mold.

Drop-Out: Portions of original artwork that do not reproduce or print, especially colored lines or background areas (often on purpose).

Dropper Bottles: A specific bottle style, available in glass and plastic, intended to accommodate closures with dropper squeeze bulbs and pipettes.

Dropper Cap: A metal or molded plastic closure with a glass or plastic dropper and small rubber or plastic bulb attached. The dropper is a glass or plastic  tube or pipette to which a rubber bulb is attached to allow the controlled dispensing of drops of liquid.

Drop Test: A test for measuring the structural integrity of a container by subjecting the packaged product to a free fall from predetermined heights onto a surface with prescribed characteristics. This test determines a package’s resistance to rupture, leakage or damage.

Drum: A cylindrical shipping container usually with a capacity from 10 to 240 litres made of steel, plastic, or fiberboard.

Dry Back: The change in color or finish of an ink film as it dries.

Dry Color: Pigment in dry or powder form.

Dry Cut: A paper defect consisting of a long cut in the paper.  This is a calendar cut occurring without wrinkling.

Dryer: The auxiliary unit of a flexographic or gravure printing press through which the printed web travels and is dried prior to rewinding.  A drying unit is also placed as required between the color stations.

Drying: The removal of moisture from the resin pellets by exposure to certain time and temperature. All Hydroscopic Material must be dried prior to molding.

Drying Ink: Ink drying in cells of a anilox roll or gravure cylinder.  In screenprinting, a state where ink has started to dry onto the screen, causing the mesh to clog and resulting in loss of detail and poor definition.

Dry-Up:  See catching up.

Dull-Coated: A moderately glossy coated publication stock, more reflective than matte, but less so than glossy.

Dummy:  A rough layout of a printed piece showing position and finished size. Alt:  A preliminary layout showing the position of illustrations and text as they are to appear in the final reproduction.  A set of blank pages made up in advance to show the size, shape, form and general style of a piece of printing.

Dunnage: Any blocking, bracing or supports used to hold a load in position or to fill empty space within a package or container to prevent damage. Often employed in distribution packages for rail and truck shipments.

Duotone: A halftone picture made up of two printed colors.

Duotone: A term for a two-color halftone reproduction form a one-color photograph.

Duplex Board: Consists of two layers and is mostly made from waste paper pulp.

Duplex Paper: Paper with a different color or finish on each side.

Duplicating Film: A film for making positives from positives, and negatives from negatives.  In color reproduction, a special film used for making duplicates of color transparencies.

Durometer: An instrument used for measuring the hardness of a material. Plastic materials can have different shore hardnesses depending on the requirements of the plastic extrusion’s final applications. The durometer measures the depth of an indentation in the material created by a given force on a standardized presser foot.

Dust Flaps: The narrow flaps extending from each side of a carton or from the sides of a top or cover that turn down into the carton before closure to keep foreign particles out.

Dwell: A pause in the applied pressure to a mold during the injection cycle just before the mold is completely closed. This dwell allows any gases formed or present to escape from the molding material.

Dwell Time: The time, usually expressed in seconds, at a given temperature that is required for the application of heat to seal a heat sealing membrane.

Dye: A colored substance, usually differing from a pigment in its solubility in various solvents.

Dye Transfer: In photography, a process of producing color prints by tanning photographic emulsions and using them to transfer dye solutions to film or paper coated with gelatin.

Dylux: Photographic paper made by DuPont, used for bluelines.

Dynamic Balance: When the rotating masses are in equilibrium.

Dynamic Range:  Density difference between highlights and shadows of scanned subjects.


EAA: See Ethylene Acrylic Acid copolymer.

Eccentricity: Off center or out-of-round condition, such as a roll or cylinder which does not rotate in a true concentric circle in relation to its axis.

Eco-Wrap: Micron Pallet Wrap. Stiffer and stronger than conventional hand wrap. Has a high resistance to stretch for superior load retention. Plastic Stretch Film and Wrap.

ECT (Edge Crush Test): A standard industry test measuring the stacking strength of a corrugated board. The amount of force needed to crush on-edge corrugated board is used to predict the strength of the total box. Minimum values must be certified.

EDG (Electronic Dot Generation): In digital imaging, a method of producing halftones electronically on scanners and prepress systems.

Edge Gate: Entrance to the part from the runner located on the parting line.

E Dimension:The outside diameter of neck on a threaded bottle neck (finish). The diameter of the neck (finish) is measured across the root of the threads.

Easy-Opening Can: A can equipped with an opening feature which can be removed or opened by hand without the need for any tools such as a can opener.

Editing: To review original copy and make necessary changes or corrections before the type is finally set.

Efficiency: Doing more with what you have or less

Efflorescence: A specific form of spontaneous desiccation (drying up). The property of a crystalline substance to become dehydrated or anhydrous when exposed to air and to crumble to a powder. Opposite of delinqescence.

Efflux Cup: A simple viscometer such as the Zahn, Shell or Hiccup, which give viscosity readings rapidly in terms of the number of seconds required for the cup to empty through an orifice of known size.  Gravure/Flexographic/Screen

Ejection Pin: A rod, pin or sleeve that pushes a molded part off of a core or out of a cavity of a mold.

Ejection Pin Marks: A residual mark on the part caused by the profile of the ejection pin.

Ejector Return Pins: Projections that push the ejector assembly back as the mold closes. Also called surface pins or return pins.

Ejector Rod: A bar that actuates the ejector assembly when the mold opens.

Elastic Elongation: The ability of a material to stretch without breaking.  To describe this properly as measured, it is more accurate to speak of “ultimate elongation” or “elongation at break” since its value, expressed as percent of original length, is taken at the moment of rupture.

Elasticity: Elasticity is the paperboard’s ability to regain its original shape after released stress. This property is closely related to tensile strength.

Elastic Memory: A characteristic of certain plastics, evidenced by their tendency to revert to a previously existing shape or dimension.

Elastomer: A rubber-like material which, at room temperature, can be stretched repeatedly to at least twice its original length and, upon immediate release of the stress, will return with force to its approximate original length.

Elastomeric: Flexible and resilient.

Electrically Conductive: Carbon-impregnated polyethylene bags providing exterior protection from static charges. Anti-Static and Static Shielding Bags

Electron Beam (EB): An alternative protective coating curing technique to ultraviolet (UV) or more conventional heat drying of varnishes or lacquers.

Electronic Color Scanner: This device brings the flexibility of electronic controls to photographic techniques in continuous tone color separations.  A high-speed computer is built into the scanner to instantaneously calculate the necessary color correction from the original copy.

Electronic Dot Generation (EDG): A method of producing halftones electronically on scanners and prepress systems.

Electronic Printing: In digital printing, any technology that reproduces pages without the use of traditional ink, water, chemistry, or plates. Also known as plateless printing.

Electronic Publishing: A new process by which information is distributed in electronic or magnetic formats. (i.e. articles available on computer services or books on CD ROM.)

Electrophotography: Image transfer systems used in copiers to produce images using electrostatic forces.

Electrostatic Assist: In gravure, use of electrostatic forces to help draw ink from cells to reduce skips in highlights.

Electrotypes: Duplicate printing plates made by the electrical deposition of copper or nickel over molds pressed from original engravings or type. For maximum press life, electrotypes may be chrome plated. For economy, several small electrotypes may be molded or soldered together to make a pattern plate from which actual duplicate printing plates are in turn produced. Used in letterpress printing.

Element Utilization: The fraction of time a given machine or element is actually producing output at a set run speed divided by the total time available for production.

Elliptical Dot: In halftone photography, elongated dots that give improved gradation of tones particularly in middle tones and vignettes – also called chain dots.

Elmendorf Test: A method for testing the tear strength of a packaging material such as paper, paperboard, tape, and other sheet materials. The test measures the energy required to extend a tear of specified length once the tear has been started by an intentional precut.

Elongation, Break: The increase in distance between two gauge marks at the break point divided by the original distance between the marks. A zero value in the field indicates that it measured less than one.

Elongation, Yield: The increase in distance between two gauge marks at a yield point divided by the original distance between the marks. A zero value indicates that it measured less than one.

Elongation: Longitudinal deformation resulting from stress, from stretching.

Embossing, Blind: The embossing of a design on unprinted paper or paperboard.

Embossing: 1) Raising letters or areas of a design above the flat surface of the substrate (i.e. carton blanks or paper sheets) by means of pressure applied through the action of male and female dies on cutting and creasing presses. 2) Embossing done by means of engraved rollers on sheet and web fed converting equipment.

EME (Electromechanical Engraver): A machine used to make gravure printing cylinders.

Em Space: A lateral space equal to the width of the lower case letter “m”. Alt:  In composition, a unit of measurement exactly as wide and high as the point size being set.  So named because the letter “M” in early fonts was usually cast on a square body.

Emulsion: Light sensitive coating found on printing plates and film. Alt:  The chemically treated side of photographic film. (The dull side not the shiny side.)  Depending on the printing process involved, film will be requested as “right reading” emulsion up or emulsion down.

Emulsion Side: In photography, the side of the film coated with the silver halide emulsion.

Enamel: A type of coating specially designed to dry to a hard, high-gloss finish.

End: (1) One of the faces of a rectangular contain­er, usually one that has the smallest area. (2) The head or bottom of a cylindrical container. In can making, can lids are referred to as ends: top end or customer’s end and bottom end or factory-applied end. (3) In set-up paper boxes, the piece of boxboard attached to the base or side of an ended box. (4) A discontinuity in a foil web or other sheet material, usually caused by breaks.

End-of-Line Packaging: The final step in most packaging lines; the process consists of cartoning, case packing and palletizing.

Engineering Plastics: A broad term covering plastics, with or without fillers or reinforcements, which have improved mechanical, chemical and thermal properties over commodity grades of resins.

Engraved Roll: Transfer roll having mechanically engraved cells.  See Anilox Roll.

Engraving: A general term normally applied to any pattern which has been cut in or incised in a surface by hand, mechanical or etching processes. In the graphic arts and converting industries, this term is often used in referring to original photoengravings from which the actual printing plates are duplicated or produced.

En Space: A lateral space equal to half an em space, roughly the width of a lowercase “n”.

Epoxy Resins: Thermosetting plastics made by the reaction of epoxies with other materials such as amines, alcohols, phenols, acids and unsaturated compounds.

EPS (EPSF) Encapsulated Postscript File:  A vector based, computer graphics file format developed by Adobe Systems.  EPS is the preferred format for many computer illustrations, because of its efficient use of memory and fine color control. Alt:  An alternative picture file format that allows Postscript data to be stored and edited and is easy to transfer between Macintosh, MS-DOS and other systems.

Equalizer Rod / Meyer Rod: A metal rod wound with fine wire around its axis so that liquids can be drawn down evenly at a given thickness across a substrate.  Flexographic / Gravure printing.

Equipment: A capital-cost-estimating category for hardware using in manufacturing, including manufacturing support.

Estimate: A statement of the probable capital appropriation scope and cost associated with changes needed to achieve a specified goal

Etch: In photoengraving, to produce an image on a plate by chemical or electrolytic action.  In offset lithography, an acidified gum solution used to desensitize the non-printing areas of the plate; also, an acid solution added to the fountain water to help keep non-printing areas of the plate free from ink.

Etching: The process of producing a design on metal or glass by causing the surface to be eaten away by a corrosive substance or cut by a sharp point tool.

Ethyl Cellulose: A cellulose ether, soluble in most organic and hydrocarbon solvents, available as a transparent flexible packaging film.  Also used as an ingredient in inks, coatings and adhesives.

Ethylene Acrylic Acid Copolymer: (Abbreviation: EAA): used for adhesion to unprimed foil, paper, and metallized film and provides substrate protection for improved structure reliability and barrier integrity.

Ethylene-Ethyl Acrylate: (Abbreviation: EEA) an organic. It is the ethyl ester of acrylic acid. It is a colorless liquid with a characteristic acrid odor. It is mainly produced for paints, textiles, and non-woven fibers. It is also a reagent in the synthesis of various pharmaceutical intermediates.

Ethylene-Vinyl Alcohol: (Abbreviation: EVOH) Used in co extruded plastic films to improve oxygen barrier properties. It is, however, a poor water vapour barrier. Even its otherwise excellent OTR, (oxygen transmission rate) is sensitive to high humidity, therefore, for packaging applications, it is usually the core layer of co extruded plastic films, where it is shielded from moisture by protective layers of polyethylene. Its OTR also depends on its VOH (vinyl alcohol) content.

EVA ( Ethylene Vinyl Acetate): A copolymer put in stretch film adding strength to ordinary polyethylene film.: Ethylene-Vinyl Acetate copolymer. Much softer and clearer than LDPE or LLDPE and has lower melt temperature. Its melt temperature goes down, while its softness increases with increasing vinyl acetate (VA) content. EVA resins with 2-18% VA content are used for cast and blown packaging films. Strengthens and improves sealability. Appropriate for use in cold-temperature applications.

Evaporation: The changing from the liquid to the gaseous or vapor stage, as when the solvent leaves the printed ink film.

Expanded Type: A type whose width is greater than normal.

Expiry Date: The date after which a perishable product should not be used, normally marked on the package, also referred to as the ‘use-by’ date.

Exposure: The step in photographic processes during which light produces the image on the light-sensitive coating.

Extenders: Materials used to weaken, or extend, a fountain ink without changing its viscosity; usually an extender varnish or an extender transparent white.

Extensibility: The ability of paper or plastic to be stretched without breaking.

Extensible: Stretchable, as in many packaging materials (such as polyethylene) which elongate during processing.

Extra Bright Foil: Foil having a uniform extra bright specular finish.

Extra Hard: Maximum hardness and tensile properties.

Extrudate: The product or material delivered from an extruder, for example, film, pipe profiles.

Extruder: A machine that makes stretch film. It consists of a large steel barrel surrounded by heaters, which melt the plastic resin pellets. Inside of the barrel is a large screw to force the liquid plastic under pressure through a die to be made into plastic sheeting by either the cast or blown processes.

Extrusion: The forcing of plastified materials (rubber, thermoplastics, etc.), generally by means of heating to fluid state and pumping by a continuous screw through a shaping die into continuous lengths of profiles, rods, pipe, film, tubing, and sheeting.

Extrusion Coating:  A process whereby paper stock is coated by extrusion, normally with plastic such as polyethylene; extrusion laminating.

Extrusion Lamination: A laminating process in which individual layers of multi-layer packaging materials are laminated to each other by extruding a thin layer of molten synthetic resin (such as polyethylene) between the layers.

Eyelet: A small hole, often reinforced, through which to insert a string or clasp, often used to attach a label or tag to a package.

Eye Spot: Sometimes referred to as an “Eye-mark”. It is a small solid image, usually in the shape of a rectangular mark that may be printed at one of the corners of each printed bag. A possible alternative to this is microdots.


F.O.B. Destination: The seller will bear transportation charges to the Ship-to location served by a common carrier where the buyer or designated person/party takes custody of the goods.

F.O.B. Plant: Buyer will bear all transportation charges, and will take custody of the products at the shipping point

Fabricating: The manufacture of plastic products by appropriate operations. This includes plastics formed into molded parts, rods, tubes, sheeting, extrusion and other forms by methods including punching, cutting, drilling, tapping, fastening or by using other mechanical devices.

Facings: 1) Sheets of linerboard used as the flat outer members of combined corrugated board. Sometimes called inside and outside liners. 2) A marketing term indicating the outwardly visible panel of a carton at retail display (facing panel) or the number of cartons displayed in a given set of vertical and horizontal dimensions; i.e., 8 facings in a 2′ x 2′ display rack.

Factory End: Bottom of can manufacturer’s end

Fadeometer: An instrument used to measure the fading properties of inks and other pigmented coatings.

Fading: The change of strength or color on exposure to light, heat, or other influences.

Failure Analysis: Analysis that assumes failure and attempts to define the paths leading to failure and what should be done to prevent it

Failure Rate: The ratio of the total number of failure to the cumulative operating time for a stated period of time. Units are failure per unit of time.

Fake Color: In color reproduction, producing a color illustration by using one image as a key and making the other separations from it manually.

False Body: Thixotropic flow property of a fluid.  When a composition thins on stirring and thickens on standing it is said to exhibit false body.

Family Mold: A mold that produces non-identical parts simultaneously from multiple cavities.

Fan Gate: A gate used to help reduce stress concentrations in the gate area by spreading the opening over a wider area. Less warping of parts can usually be expected by the use of this type of gate.

Fanout: In printing, distortion of paper on the press due to waviness in the paper caused by absorption of moisture at the edges of the paper, particularly across the grain.

Faraday Cage: Provides both interior and exterior protection from static and other charges.

Fastener: Any device which serves to secure one part of a package to another. Examples: nail, screw, staple, strapping, stitch, adhesive, etc.

Fastness: Term used to denote the stability or resistance of stock or colorants to influences such as light, alkali, etc.

Fast Solvent: Solvent of low boiling point that evaporates rapidly; a fast-drying solvent.

Fatigue Strength: The maximum cyclic stress a material can withstand for a given number of cycles before failure occurs.

Feasibility Studies: Experimental studies on a process or equipment to access what results are achievable and/or what will be required to produce a desired result.

Feathering: A ragged or feather edge that shows at the edge of type or cuts.

Feeder: In printing presses, the section that separates the sheets and feeds them in position for printing.

Feed Screw: (1) A metal or plastic cylinder with helical contoured grooves in its surface to fit the container, which is turned to move a container along a given path, normally into or out of a machine. (2) The screw of an extruder which moves, compresses and heats the extruded material.

FEFCO: European Federation of Manufacturers of Corrugated Board

FEFCO Case Codes: A standardized set of patterns used for corrugate in industry, often seen as a four digit number.

Felt: The porous belt which carries the newly formed paperboard through the papermaking machine until the sheet is stable enough to continue without support.

Felt Side: The smoother side of the paper for printing.

Fiber: 1) A small thread-like cellulose unit of vegetable growth obtained from plants such as trees, sugarcane, cotton, jute, etc., from which paper and board are made. 2) In packaging, fiber forms the foundation of converted paperboard products such as fiberboard, fiber boxes, fiber containers or fiber drums.

Fiberboard: The general term indicating boxboard that contains center plies of a different furnish than that used for the top and bottom liners. A name used for papers used in corrugated board.

Fill: The packing of the cavity or cavities of the mold as required to give a complete part or parts that are free of flash and porosity.

Filler: 1) The inner ply or plies of a multiple layer boxboard. 2) A loading material, such as clay, use in coating paper or board. 3) Strips of paperboard, crushed paper of other substances used to fill the voids within a package. See also: Dunnage

Filling In (or Filling Up): In letterpress or offset lithography, a condition where ink fills the area between the halftone dots or plugs up (fills in) the type.

Filling Machine: A device that measures a predetermined volume, weight or number of product and fills it into a bag, bottle, box, container, sack, tube or other type of package.

Fill Pattern: The contours of the advance of the material as the cavity fills. (See flow pattern)

Fill Pressure: The pressure required to fill the cavity.

Fill Time (also known as Injection): Time required to fill the cavity or mold.

Film, Cast:  Generally refers to films made by coating, or casting, a solution of a film former on an endless belt, drying the solvents, stripping the film from the belt and winding it up.  Polyethylene cast film refers to the film made by extruding the molten polyethylene through a flat die onto a series of relatively cool rolls to chill it and winding-up the film so formed.

Film: A flexible plastic material, generally transparent, used as windows in cartons; or for overwraps and laminates. It is extruded, cast or calendered.

Film Former: A type of resin (binder) with qualities of forming a tough, continuous film; usually refers to such plastics as ethyl cellulose, nitrocellulose, chlorinated rubber and vinyl used in inks and coatings.

Film Gauge:  A number indicative of the thickness of films.

Film Treatment:  Oxidizing the surface of film to increase adhesion of inks.

Fines: In the classification of powdered or granular materials such as molding compounds according to particle size, fines are the portion of the material composed of particles which are smaller than a specified size.

Finish: (1) The quality of a surface as determined by color, brightness, texture, and general appearance. (2) That part of a glass container which carries the threads, lugs or other features to which the closure is applied.

Finite Element Analysis: The solution of simultaneous equations for each element with resulting pressure, temperature and elapsed time at each node.

Fish Eyes: A scalloped surface on a finished product surface.

Fitment: A package component attached to the con­tainer finish to provide a  per­formance function such as control of fluid flow and/or cut off, or to provide restricted product dispensing. They are usually protected by the primary closure and perform the desired function once the closure is removed. As part of a closure assembly,  fitments thus can act as droppers, sprinklers, powder shakers or spreaders.

Five Sided Wrapping: Wrapping a pallet load’s four sides plus the top. The top of a pallet can be wrapped by using the cross top wrapping technique.

Flame Retardant: Having the ability to resist combustion. A flame retardant plastic is considered to be one that will not continue to burn or glow after the source of ignition has been removed.

Flange: The extended lip of the hand brake that keeps the operator’s hand from sliding down and rubbing against the roll.

Flanged Bottom: A bottom defect. A rim of glass around the bottom of the ware at the mold parting line.

Flap: Extension of the side wall panels that, when sealed, close the remaining openings of a corrugated container or a folding carton.

Flap Lock: Bag that has the lip folded back with side seals. Commonly known as a sandwich bag.

Flash: Any excess material that is formed with and attached to the component along a seam or mold parting line.

Flash Gate: Wide gate extending from a runner which runs parallel to an edge of a molded part along the parting line of a mold.

Flask: A style of narrow-neck bottle, usually of elliptical cross section, with flattened side walls having a width of four or more times the thickness.

Flat Bags: Two-dimensional bag (width x length) with bottom or side seals. Flat Poly Bags

Flatbed: Flatbed equipment for cutting, creasing, and embossing refers to operations being carried out with the tool acting in a vertical direction towards a horizontal make-ready (or counter-die).

Flatbed Die-Cutter: Die-cuts for corrugated blanks. The cutting dies are flat steel-rule dies versus rotary. Machines vary in size and options.

Flatbed Scanner: A device that scans images in a manner similar to a photocopy machine; the original art is positioned face down on a glass plate.

Flat-Bottom Stand-up Pouch: A stand-up pouch that is made from one piece of film. The front, gusset, and back are continuous, so there is no seal at the gusset. Holds more weight than Doy-style pouches, so are commonly used for heavy products.

Flat Crush Test: Measure of the ability of the fluting of a corrugated board to resist compressive stress applied to the faces of the board.

Flexibility: The property of a material which will permit its being bent or twisted without breaking; the state of being non-rigid.

Flexo Folder Gluer: A high speed machine that converts corrugated board into shipping boxes by printing, folding, cutting, and gluing the sheets.

Flexographic Printing: (Abbrev: flexo) An economical printing method, mostly done on web-fed equipment, in which a rubber roll, partially immersed in an ink fountain, transfers ink to a fine-screened steel roller carrying the design to be printed, which in turn deposits a thin layer of ink on the printing plate. On the plate, the print pattern is raised and the non-print area is lower. The ink is applied to the raised area of the rubber plate, then transferred to the material to be printed in the desired pattern. Flexographic printing produces remarkably sharp reproductions of multicolor work, including lettering in small type sizes. Also called aniline printing because flexographic inks originally used aniline dyes.

Flexural Modulus: The ratio, within the elastic limit, of the applied stress on a test specimen in flexure to the corresponding strain in the outermost elements of the specimen.

Flexural Strength, Yield: The measure of resistance of the material to fracture during bending.

Flexural Strength: The maximum stress in the outer fiber at the moment of crack or break. In the case of plastics, this value is usually higher than the tensile strength.

Flint: Flint is perfectly clear transparent glass, like window glass, used for all types of containers.

Flock: Finely cut cloth fibers blown or shaken on adhesive-coated boxboard or cartons to produce a velour or suede finish.

Floor Loading: A technique used for packing a truck in which pallets and stretch film are not used. Hand carrying (conveyors are frequently used) a load on a truck and shipping the load by leaving it on the trailer floor.

Flow Balancing: Modifying flow paths, particularly runner sections, so that all flow paths within a mold fill in equal time with equal pressure.

Flow Leader: Local increase in thickness to encourage flow in a particular direction.

Flow Marks: Wavy surface appearances on a molded part caused by improper flow of the melt into the mold.

Flow Pattern: The contour the melt takes sequentially as it fills the cavity.

Flow Rate: The volume of material passing a fixed point per unit time.

Flow sheet (FS): A schematic presentation of a process

Fluidity: Reciprocal of Viscosity

Flute: A wave or corrugation on the surface of the medium; one of the pleats of a piece of corrugated sheet. (E flute=approx. 1/16″, B flute=approx. 1/8″, C flute=approx. 3/16″ and doublewall=approx. 5/16″)

Fluting: Paper that has been corrugated with heat and pressure to provide the central layer in corrugated board and separate the liners while providing strength and rigidity. See also: Corrugated medium

Fluting Profile: Varying degrees of fluting width and spacing that enable greater cushioning or structural strength depending on package needs.

FM (Frequency Modulation) Screening: A computerized method for digital screening.

Foaming Agent: Any substance which alone or in combination with other substances is capable of producing a cellular structure in a plastic mass.

Fogging: A method of applying corrosion-preventing materials in the form of vapour to interior surfaces or relatively inaccessible sur­faces of packages for corrodible articles.

Foil: Thing gauged aluminum used in packaging as a laminate to board, or as an overwrap, to increase eye appeal and to provide functional properties such as resistance to heat, grease and water.

Foil Stamping: The impressing of lettering or a design through foil upon a carton blank by means of a heated die or type. Also called “hot stamping.”

Foldability: Foldability is the ability of creases to be folded so that they show permanency, good definition, and low spring-back. Ideally, the fold should act like a hinge. This ability depends on a complex combination of factors such as tensile strength, compression strength, delamination strength, bending resistance, flatness, and dimensional stability. These are crucial properties for the paperboard’s ability to “forgive” the permanent deformation of deep and narrow creases and to retain the intended shape of the folds.

Folder-Gluer: A machine for folding a scored and slotted paperboard or corrugated sheet (box blank) and making the side (manufacturer’s) joint by glueing to produce a flattened box.

Folding: After the paperboard has been creased, the folding operation should always be carried out towards the bead.

Folding Boxboard: Single or multilayer paperboard made from primary and/or secondary fibres. Used primarily for packaging dry or moist consumer goods in cartons.

Folding Carton: A container made by bending grades of paperboard or plastic (plain or printed), cutting and creasing in a variety of sizes and shapes, folding and then delivering to the user in a flat, or glued and collapsed form. Formed by the manufacturer to be set up, filled and closed by the user. Folding cartons are constructed in a multitude of styles, some of which include: tuck-end carton, seal-end carton, reverse tuck, straight tuck, two piece, display cartons, and many others.

Folding Endurance: A property of paper and board that represents its ability to withstand the stress of repeated folding.

Folding Factor: The folding factor is the ratio between bending resistance for creased and uncreased paperboard. Folding factor 0 corresponds to uncreased paperboard, folding factor 100% corresponds to a perfect hinge.

Folding Resistance: High folding resistance requires high bending force. Deep and narrow creases along well-defined fold lines provide low folding resistance.

Form, Fill and Seal Machines: Packaging machines which form, fill and seal a package in the same machine.

Formability: Formability refers to the ability of paperboard to be used for the creation of complex two-or three-dimensional shapes. Formability is related to features such as elasticity, creasability, foldability, and different strength characteristics.

Format: The type size, style, typeface, margins, bleed, gutters, printing requirements, etc., of a printed piece.

Forme: A cutting and creasing tool used to create intricate designs during die-cutting.

Forming Mold: (also “Finish Mold”) Sometimes referred to as the bottle mold, is the mold in which the bottle is blown into its final shape after being preformed in a blank mold.

Form Rollers: The rollers, either inking or dampening, that directly contact the plate on a printing press.

Form Stability: Form stability is the ability to retain a certain form during handling and use. Important features are compression strength, delamination strength, and dimensional stability.

Forty-eight/Forty (48/40): Term referring to a pallet size of 48″ by 40″ which optimizes space utilization of trailers and most warehousing systems.

Fountain Solution: In lithography, a solution of water, a natural or synthetic gum, and other chemicals used to dampen the plate and keep non-printing areas from accepting ink.

Four-Color Process: In order to create full color graphics, four halftone plates use the primary printing colors cyan, yellow, magenta, and black, laying them down in precise orientation.

Four Color Process Printing: Also called process printing – Indicates the four-color plates or cylinders commonly used in color printing. Usually of photographic quality. (C – Cyan, M – Magenta, Y – Yellow, K – Black.) In flexographic printing the minimums are much higher, and the cost more substantial than in spot color printing.

Fourdrinier Machine: A paper-making machine on which paper is formed by depositing pulp furnish onto an endless wire mesh conveyer.

FPO (For Position Only): In digital imaging, this is typically a low-resolution image positioned in a document to be replaced later with a higher resolution version of the same image.

Fracture: The separation of a body, usually characterized as either brittle or ductile.

Frame: Structural description of the end and/or side wall components of a tray type of folding carton, diecut and scored to form a shoulder or enclosing border to protect and enhance the display of the contents.

Free Vibration: After an initial displacement, the system will continue to vibrate at its natural frequency if no other force acts upon it. See also: Vibration; Forced Vibration

Freeze Off: The temperature of the material is reduced to the point that it blocks an area it would fill if it were hotter.

Freight on Board (FOB): The term used to signify that the seller is required to bear all costs required to place the good abours equipment of the transporting carrier.

Frequency: Number of oscillations completed per unit time.

Frictional Heating: Heat generated by the friction of the chains of molecules slipping past each other or over a surface.

Frosting: A crystalline finish or pattern on a glass surface.

Furnish: The mixture of pulp, paper scrap, sizing, water, dyes, and other additives fed to the wet-end of a paper or board making machine from which paper or board is formed. The wet-end furnish is appox. 94% water; finished sheet ranges from 5% to 7% water.

Fugitive:  1) Poor color fastness because of exposure to light, heat or other agents. 2) Term used to describe unstable plasticizers that leave a printed film because of their volatility.

Fuse: To join two glass, metal or plastic surfaces by heating them just beyond their melting or softening point.

Fusible: Capable of being melted or liquefied by action of heat.


G.C.M.I. (Glass Container Manufacturers Institute): Former name of G.P.I.

G.P.I. (Glass Packaging Institute): An organization composed of glass container producers. GPI establishes policies, such as standardization and develops industry advertising programs.

Galley Proof: Text copy before it is put into a mechanical layout or desktop layout.

Galvanize: To coat iron or steel with zinc by electroplating or hot dipping to retard rusting.

Gamma: A measure of contrast in photographic images.

Gamma Irradiation: Sterilization by means of exposure to a source of gamma rays, normally Cobalt 60.

Gang: Getting the most out of a printing press by using the maximum sheet size to print multiple images or jobs on the same sheet.  A way to save money.

Gantt Chart: A graphic presentation of project activities shown by the time-scaled bars with the length of the bar equal to the duration of the activity

Gapless: Plate or blanket cylinders without gaps.

Gate: The channel through which the molten resin flows from the runner into the cavity.

Gate Blush: A blemish or disturbance in the gate area of an injection molded article.

Gate Trim: Remnant of plastic left over from cutting the component from the runner or sprue, usually to be cut flush with the edge of the component.

Gathering: In binding, the assembling of folded signatures in proper sequence.

Gauge: A term used in referring to the thickness. The higher the gauge, the thicker the material. Also gage.  1) (Noun) an instrument for exact measuring. 2) (Verb) to measure exactly. 3) A standard measure, usually of thickness or diameter, expressed by a number which has a standard dimensional equivalent that varies for different materials and for different standards.

1mil = 1/1000 of an inch = .001

1 mil = 25.4 microns

1 micron = one millionth of a meter

1 inch = 25.4 mm = 2.54 cm

100 gauge = 1 mil

80 gauge = 8/10 mil = .0008 inches

Gear Chart, or Gear Selector:  A handy reference compilation of the various printing lengths, or repeats, obtainable within the different gearing systems.

Gear Marks:  A defect in flexographic printing.  Usually appears as uniformly spaced, lateral variations in tone exactly corresponding to the distance between gear teeth.

Gear Side:  See driving side.

Gear Streaks:  In printing, parallel streaks appearing across the printed sheet at same interval as gear teeth on the cylinder.

Gel: Small piece of undissolved resin causing imperfection in film.

Ghost Bars:  A quality control method used to reduce ghosted image created by heat or chemical contamination.

Ghosting:  A faint printed image that appears on a printed sheet where it was not intended.  More often than not this problem is a function of graphical design.  It is hard to tell when or where ghosting will occur.  Sometimes you can see the problem developing immediately after printing the sheet, other times the problem occurs while drying.  However, the problem occurs it is costly to fix, if it can be fixed.  Occasionally it can be eliminated by changing the color sequence, the inks, the paper, changing to a press with a drier, printing the problem area in a separate pass through the press or changing the racking (reducing the number of sheets on the drying racks).  Since it is a function of graphical design, the buyer pays for the increased cost.

GIF:  An eight bit (256 colors or shades of grey) or less computer file format.  Though commonly used to post photographic images to computer bulletin boards, GIF files are almost never used for professional printing.

Glass Coating, Safety: Stock and custom glass containers with special safety and shatterproof coatings.

Glass Fibers: A family of reinforcing materials for reinforced plastics based on single filaments of glass.

Glassine: A supercalendered, smooth, dense, transparent or semi-transparent paper manufactured primarily from chemical wood pulps. It is grease resistant and when waxed, lacquered or laminated is highly impervious to the transmission of moisture vapor. It is used extensively as a protective carton liner or inner bag for food and many other products.

Glass Transition: Change in an amorphous polymer from viscous to hard and relatively brittle.

Glass Types: Four types of glass are specified by the U.S. Pharmacopoeia on the basis of chemical durability tests. Types I, II, and III are intended for packaging parenteral preparations and Type NP for non-parenteral products. Type I: Containers normally made of borosilicate glass having a highly resistant composition. Type II: Containers made of commercial soda-lime glass which have been treated on the inside surface at a high temperature to obtain a great improvement in chemical resistance. Type III: Untreated glass containers made of commercial soda-lime glass of average or somewhat above average chemical resistance. Type NP: Untreated glass containers made of ordinary soda-lime glass.

Glassware: Stock and custom glassware, including bowls, stemware, candle holders, vases, plates and perfume bottles.

Gloss: The term used to express shine, sheen or luster of the surface of boxboard or cartons. It varies according to the nature of the board stock itself, or may be imparted to the board or carton blank by coating, printing, or laminating.

Glue: A commonly used synonym for the word adhesive. The term should actually apply only to those gelatinous adhesives extracted from the bones, skin, etc., of animals and fish by hot water.

Glueability: The established criterion for glueability is the tear behaviour of a glue seam between the pigment-coated surface and (usually) the reverse side of the paperboard. Since graphic paperboard can have a different finish on its reverse side, a paperboard with suitable gluing properties can always be chosen. Of course the glueability is different for different gluing systems.

Glue Flap: Structural element of a folding carton blank used to adhesively secure one panel to another.

Glue Line: The line of adhesive between the two surfaces to be adhered.  Also paste line.

Gluer, Erector: An automated machine for gluing and sealing cases.

Gob: A lump of molten glass with a specific shape, temperature, viscosity, and weight. The gob will be processed by the IS Machine into a glass container.

Goldenrod Paper: In offset lithography, a specially coated masking paper of yellow or orange color used by film strippers to assemble and position negatives for exposure on plates.

Good Manufacturing Practices (GMP): A document that describes agree-to best or optimal procedures for manufacturing

Grain: The longitudinal arrangement of the fibers in paper or paperboard which results as they settle in the direction parallel with the travel of the paper or board machine. Direction of the grain is important in carton design because greater tearing strength exists across the grain, and greater tensile strength in grain direction. Grain is more pronounced in paperboard made on a cylinder machine than on paperboard made on a fourdrinier machine.

Grain Direction: The direction taken by a majority of the fibers in any sheet of paper.  Synonymous with “machine direction”, the opposite of “cross direction”.

Grammage: A term in the metric system for expressing the basis weight of paper.  It is the weight in grams of a square meter of the paper expressed in g/m2.

Graphic:  A non-text item (illustration or photograph) to be printed.

Graphical Paperboard: Graphical paperboard is paperboard in which both the baseboard and the coatings are constructed to provide excellent print quality and high runnability in all printing and finishing operations. Sometimes we use the terms paperboard and multi-ply paperboard interchangeably. The reason is that all our paperboard products are of multi-ply construction.

By using different types of pulp in different plies (layers) and combining this with various sheet constructions and coatings, the multi-ply technique allows us to tailor the paperboard features to suit a wide variety of high quality demands in the graphics industry. To achieve a smooth surface, short fibers are used in the surface layers. For elasticity, strength and the sense of quality from a dense paperboard, a greater proportion of long fibers are used in the middle layers. It is also possible to use the same fibers for every layer and apply different preparation treatments to them.

Graphic Design:  A process of problem solving, using visual elements (pictures and type) usually to communicate a concept or idea.

Graphics: The design and decoration of the surfaces of a package. The use of the photographic and printing techniques for label and package decorating.

Gravity Conveyor: A conveyor system that uses solely gravity to drive the products

Gravure Printing: (Rotogravure). With gravure printing an image is etched on the surface of a metal plate, the etched area is filled with ink, then the plate is rotated on a cylinder that transfers the image to the film or other material. Gravure is abbreviated from Rotogravure. Gravure printing is ideal for printing in long runs and contributes to higher printing speeds. Gives excellent reproduction of detail to the image printed.

Gray Balance: The dot values or densities of cyan, magenta, and yellow that produce a neutral gray color.

Gray Level: The number of gray values that can be distinguished by a color separation filter – usually 256.

Gray Scale: A strip of standard gray tones, ranging from white to black, placed at the side of original copy during photography to measure tonal range and contrast (gamma) obtained.

Greaseboard Proof: Paperboard which has been treated or laminated to provide resistance to the penetration of greasy or oily substances. Treatment may include such coatings as casein, lacquer, hot melt, polyvinyl, resin or silicate. Glassine and other greaseproof papers may be laminated to board to provide this quality.

Grease Proofness: Resistance of material to grease.

Gripper Edge: The leading edge of paper as it passes through a printing press. Also, the front edge of a lithographic or wrap-around plate secured to the front clamp of a plate cylinder.

Gripper Margin:  Unprintable blank edge of paper on which grippers bear, usually 2 ” or less.

Grippers: In sheetfed printing presses, metal fingers that clamp on paper and control its flow as it passes through the press.

Grooving the Cylinder:  Cylinder damage due to foreign material.

Grossage: A quantity in terms of gross. Grossage is the usual denomination used in glass container terminology.

Grounding:  Removal of electric charges by leading them into the ground through electrical conductors.

Gum:  A water-soluble amorphous substance exuded by or prepared from plants, which is sticky when moist but hardens upon exposure to air; any material having the above properties, natural or synthetic, regardless of source. Loosely used in reference to unvulcanized rubber.

Gum Arabic: In offset lithography, used in platemaking and on press to protect the non-printing areas of plates.

Gusset: The bellows fold or tuck on the side or bottom of a bag; the capacity of the bag is measured with the gusset unfolded.

Gusseted Bags: Flat style bag with both sides or bottom tucked in to form gussets. Designated with three dimensions; Side Gusset (width x depth x length) or Bottom Gusset (width x length + gusset).

Gutter: The blank space between page columns or the inner or outer margin space from printing area to left and right of the page edges. More space is usually required in the binding fold area.


Hairline:  A very thin line or gap about the width of a hair or 1/100 inch.

Hairline Register:  Printing registration that lies within the range of plus or minus a 1/2 row of dots

Halation:  In photography, a blurred effect, resembling a halo, usually occurring in highlight areas or around bright objects.

Halftone:  Converting a continuous tone to dots for printing. Alt:  A reproduction of a continuous-tone image (i.e. a photograph or painting), through a screening process, using fine dots of varying size and spacing to reproduce the shades and textures of the original.

Halftone Engraving: A metal or plastic plate from which the tone values of halftone reproduction are obtained during the printing operation. While the term may be used alone it is usually prefaced by another word to indicate the material from which it is made; such as copper, zinc, magnesium or plastic.

Halftone Negative (or Positive): The exposed photographic film or glass onto which the tone values of a subject are converted through a halftone screen. The negative or positive image is transferred in the succeeding steps toward the preparation of a halftone film for plate/cylinder preparation.

Halo:  An undesirable peripheral outline of the printed image.

Hand Erect: A package assembled by hand; usually used during small runs or complex designs.

Hand-Set:  When type is put into a composing stick by hand instead of by machine.

Hand Wrap Film: Thin film that is applied with a handheld device to a palletized load to prevent any movement while it is in transit.  

Hard Chromium:  Chromium plates for engineering, rather than decorative applications.  Not necessarily harder than decorative chromium.  Gravure applications are hard chromium.

Hard Copy:  The permanent visual record of the output of a computer or printer.  Also the material sent to a typesetter in typed form, for conversion into typeset material. Alt:  The output of a computer printer, or typed text sent for typesetting.

Hard Dot: Halftone dot with little or no fringe that prints with little or no dot gain or sharpening.

Hardener: A substance or mixture of substance added to a material to increase or control the curing reaction by taking part in it.

Hardness: The resistance of a material to compression, indentation and scratching.

Hard Proof: A proof on paper or other substrate as distinguished from a soft proof that is an image on a screen.

Hard Sized:  Refers to a type of paper that has been treated with considerable size to resist water. Opposite of slack-sized.

Hardware: Computer and peripherals as distinguished from software, which is a program for operating hardware.

Haze: The cloudy appearance of a material caused by light scattered from within the specimen or from its surfaces.

H Dimension: The height of the bottle finish measured from the sealing surface, in a line parallel to the axis of the finish and tangent to the threads on the finish, down to a point where the line intersects the body (shoulder) of the container. The inside height of the closure measured from the bottom of the closure, in a line tangent to the threads of the closure and terminating at the inside, top of closure.

HDPE: High density, (0.95-0.965) polyethylene. Has much higher stiffness, higher temperature resistance and much better water vapour barrier properties than LDPE, but it is considerably hazier.

Header Bags: Side-weld bag with continuous seal along top, 2″-3″ below fold. Bag is loaded and sealed from the bottom and typically has a hang hole.

Headspace: The empty space inside a container between the top surface of the product and the inside upper surface of the container. See also: Ullage

Heat Resistance: The ability to withstand the effects of exposure to high temperature.  Care must be exercised in defining degree.

Heat Seal:  A method of uniting two or more surfaces by fusion, either of the coatings or of the base materials, under controlled conditions of temperature, pressure, and time (dwell).

Heat Seal Coatings: Materials applied to board, in a liquid form, and dried which may be reactivated by heating to about 225° to 250° F.

Heat-Seal Label: A label made of paper or other material coated on one side with a heat-seal coating, usually a thermoplastic resin, and characteristically difficult to remove after application.

Heat Seal Lacquer:  A lacquer which, when applied to a stock and dried, is capable of softening under heat and can be sealed to itself or other surface.

Heat Seal Layer: A heat sealable innermost layer in plastic packaging films and laminates. Can be either adhesive laminated or extrusion coated onto a non-sealable film (or foil).

Heat Seal Strength: Strength of heat seal measured after the seal is cooled, (not to be confused with “hot tack”).

Heat Stabilizers: These additives increase the ability of the material to withstand the negative effects of heat exposure. They are used to increase the overall service temperature of the material.

Heat Transfer Labelling: Widely known by the proprietary name Therimage, the label is transferred from a plastic web to the pack by heating which activates an adhesive on its surface. Used for high-value products in glass and plastic containers, but superseded in many cases by transparent PS labels.

Heavy Bottom: A bottom defect. A localized thick area in the bottom which is usually thickest in the center of the bottom.

Heavy Metals: Metallic elements of relatively high atomic weight that, upon exposure, tend to collect in specific body organs and at high levels are known to be toxic. Historically, lead solders were used to seal metal can seams and most printing ink pigments were derived from compounds containing heavy metals such as lead, arsenic, cadmium, mercury, selenium, barium, chromium and antimony.

Heel: The lower portion of a glass or plastic container, starting with the bearing surface of the bottom and including a small portion of the lower side-wall.

Heel Radius: The degree of curvature at the extreme bottom end of a bottle extending upward from the bearing surface. Also called base radius.

Heel Tap: A bottom defect. A localized thick area at one side of the bottom.

Helix Angle: The measure of inclination of the thread, from a plane perpendicular to the vertical centerline of the thread finish.

Hermetic Seal: An airtight seal.

Hesitation Effect: Occurs in parts of varied thicknesses. The flow moves preferentially into a thicker area causing an adjacent thin area to freeze off while the thicker area fills. Gates should be positioned as far as possible from where the flow divides into thick and thin flow paths.

Hiccup:  A form of efflux cup viscometer.

Hickeys: In offset lithography, spots or imperfections in the printing due to dirt on the press, dried ink skin, paper particles, etc.

High Density Load / Product: A load or product that is relatively heavy (i.e. – an engine block on a pallet).

High Density Polyethylene: Thinner, yet stronger than low density polyethylene. Moisture and vapor barrier, non-porous.

High Impact Polystyrene: (Abbreviation is HIPS) a low cost plastic material that is easy to machine and fabricate. HIPS is often specified for low strength structural applications when impact resistance, machinability, and low cost are required. It is frequently used machining pre-production prototypes since it has excellent dimensional stability and is easy to fabricate, paint and glue. Natural (translucent white) HIPS is FDA compliant for use in food processing applications.

Hilo: Also called a hi-lo. Double-wall corrugated board combining both A-flutes and B-flutes.

Hinged Lid: A container closure which is attached to the container by a flexible or bending joint. The hinge can be a separate unit or can be an integral part of the container.

Holdout: In printing, a property of coated paper with low ink absorption that allows ink to set on the surface with high gloss. Papers with too much holdout may transfer ink to other sheets.

Hole Punch: A mechanical device used to produce an air evacuation hole.

Hollow Neck: A neck defect. A neck in which the glass has blown away, leaving it with thin walls.

Holography: The method of producing a three dimensional image in foil or film utilizing interference patterns from a split laser beam.

Homogeneous:  Of the same uniform composition or construction throughout.

Homopolymer: Plastic that results from the polymerization of a single monomer.

Hopper: Machinery that helps orient the packages in the right direction

Hopper Dryers: Auxiliary equipment that removes moisture from resin pellets.

Hopper Loader: Auxiliary equipment for automatically loading resin pellets into machine hopper.

Hot Check: An edge or side defect. A check characterized by deep V-shaped cracks appearing on the edge or side.

Hot Dip: Traditional process for coating both sides of a steel sheet with commercially pure tin to produce tinplate. The amount of tin coating on each side of the sheet can be varied to meet performance requirements. Largely superseded by electrolytic coating that applies a thinner layer of tin.

Hot-Runner Mold (also known as Insulated Runner or Runnerless Molding): A mold in which the runners are insulated from the chilled cavities and are kept hot. Hot-runner molds make parts that have no scrap.

Hot Slip: The amount of force required to slide two surfaces of heated film against one another.

Hot-Stamping: A decorating operation by which a design is transferred from a roll of thin aluminium foil to a surface by means of impressing it with heated metal dies.

Hot Tack: Strength of heat seal measured before the seal is cooled, which is very important for high-speed packaging operations.

HSV: Acronym for hue, saturation, and value (or brilliance or luminance) – a color space used in some graphic programs.

Hue: In color, the main attribute of a color that distinguishes it from other colors.

Humidifier:  A device that causes water vapor to be diffused into the atmosphere of an enclosed area.

Humidity:  The moisture condition of the air.  Actual humidity is the number of grains of moisture in the air at any given time.  Relative humidity is the percent of moisture relative to the maximum which air at any given temperature can retain without condensing into precipitation.

Humidity Cabinet: A box or room constructed with a conditioning device used to maintain a specified relative humidity at a specified temperature. Used in testing packages for their moisture resistance and barrier properties.

Hydrocarbon:  Materials composed entirely of carbon and hydrogen.  General term for family of petroleum solvents.

Hydrometer:  An instrument used for measuring the specific gravity of a liquid.

Hydrophobic: Water repellent; image areas, for example, on an offset plate “hate” water. The opposite is hydrophilic.

Hygrometer:  An instrument for measurement of the relative humidity of air.

Hygroscopic: Paperboard is a hygroscopic material, which means that it adapts to the environmental moisture content and reacts to changes in humidity by swelling during moisture uptake and shrinking when losing moisture.

Hysteresis:  A loss of energy due to successive deformations and relaxation.


I.S. Machine (Individual Section Machine): Used for the formation of glass containers. It has the ability to have one or more sections taken out of production for maintenance while the remaining sections continue making containers.


ICC (International Color Consortium): The ICC was established in 1993 for the purpose of creating and promoting the standardization of an open, vendor-neutral, cross-platform system for managing color in any medium.

Icicles:  Strings of dried ink hanging around the cylinder area including applicator, bafflers, etc.

ID: Inside diameter of a container or container part, ordinarily of the container shell or body.

Identi Film: Pallet stretch film in colors. Tinted films give protection from tampering and theft. Improves load appearance, product rotation.

I Dimension: A specified minimum diameter inside the bottle neck. A minimum diameter is specified to allow sufficient clearance for filling tubes to enter the bottle neck easily.

Idler rolls:  Roller mechanisms on converting machines used to support, smooth or direct the web in its course of travel through a machine.  Not driven.

Illustrator:  An individual who draws or paints original artistic images for use in commercial art.

Image:  A design or drawing.

Image Area:  Portion of paper on which ink can appear.

Image Assembly:  See stripping.

Image Carrier:  Any plate, form, cylinder or other surface which contains an image, receives ink, and transfers it to another surface or substrate, e.g., gravure cylinders, offset plates, and letterpress stereotypes.

Imagesetter:  A high-resolution device that prints directly to plate ready film.

Impact Modifiers: Additive used to enhance the material’s ability to withstand the force of impact.

Impact Resistance: Resistance of a material or package to shocks from dropping or from sharp blows/knocks.

Impact Strength: (1) The ability of a material to withstand shock loading. (2) The amount of energy needed to fracture, under shock loading, a specified test specimen in a specified manner.

Impact Test: A test to determine the effect of various shock forces on packages or packaging materials.

Impression: (1) A mark, especially an indentation, made by a die, stamp, printing press or other marking device. (2) One copy or one color of a design made by passing a sheet once through a printing press. (3) A mold cavity; more specifi­cally, a single cavity of a multi-cavity mold.

Impression Bar:  A small diameter rod or bar, supported by a back-up member of sufficient rigidity, mounted in place of the impression cylinder for running certain types of work, e.g., porous tissue.  Gravure, Flexographic

Impression Cylinder: In printing, the cylinder on a printing press against which the paper picks up the impression from the inked plate in direct printing, or the blanket in offset printing.

Imprint: 1) The trademark or legend reproduced on a carton during the process of printing to identify the manufacturer. 2) The subsequent printing of additional identifying information on a previously printed carton blank such as stock retail boxes.

Impulse Sealer: Also known as a heat sealer. These units use an electrical current passed through a Ni-Chrome wire heating element to seal bags & tubing. Can be used on many plastic materials to create strong permanent welds.

Indicia: Postal information placed on a printed product.

Induction Sealing: A sealing technique in which excitation by means of high frequency electric impulse causes materials to bond. Usually associated with inner seals, whether they are applied separately or as an integral part (metal or plastic) of the closure.

Infeed:  A mechanism designed to control the forward travel of the web into the press.

Infeed Table: A fixed table that is set in front of the case sealer where an unfilled box can be placed for filing

Infrared (IR): Invisible, low energy light of wavelengths longer than those of visible light, felt as heat. In the folding carton converting process, a technology used to instantly cure or set inks or coatings on the printing press. IR is an alternative to conventional heat or UV setting (drying) of inks or coatings.

Inhibitor: A substance added to the furnish, coating or laminate of boxboard to retard or prevent deterioration of a carton or its contents by chemical reaction.

Injection (also known as Fill Time): Time required to fill the cavity or mold.

Injection Blow Molding: Blow molding process by which the plastic parison to be blown is formed by injection molding.

Injection Molding: The method of forming objects from granular or powdered plastics, most often of the thermoplastic type, in which the materials is fed from a hopper to a heated chamber in which it is softened, after which a ram or screw forces the material into a mold. Pressure is maintained until the mass has hardened sufficiently for removal from the mold.

Injection Molding Pressure: The pressure applied to the cross-sectional area of the molding cylinder.

Injection Pressure: The pressure on the face of the injection screw or ram when injecting material into the mold, usually expressed in PSI.

Ink:  A fluid or viscous substance consisting of pigments, dyes or other materials dispersed in a carrier or vehicle by means of which a printing press imparts the desired image on boxboard. Character of the ink varies according to the printing process and application.

Ink Flexographic:  Fast drying fluid or paste type inks for flexographic printing.

Ink Fountain: In printing presses, the device that stores and supplies ink to the inking rollers.

Ink Holdout: A paper’s ability to resist penetration of ink components beneath its surface.

Ink-Jet Printing: In digital printing, a plateless printing system that produces images directly on paper from digital data using dots or streams of very fine drops of dyes and pigments that are controlled by digital signals.

Ink Mist:  Flying filaments or threads formed by long inks like newspaper ink.

Inkometer:  An instrument for measuring the tack of printing inks.

Ink Receptivity: The degree of penetration of printing inks on the surface of boxboard.

Inline: Packaging of a material occurs in a forward motion in a single file line

In-Line Press:  A press coupled to another operation such as bag-making, sheeting, die-cutting, creasing, etc.  A multi-color press in which the color stations are mounted horizontally in a line.

Inner Liner: Paper material used for the inside of corrugated board. The appearance is not as important as outer liner, but it could be subject to regulatory requirements if it comes in contact with food.

Inner Packing Forms: Die cut corrugated that is used to support irregular products from below or lock them into place from above.

Inner Packing Pieces: Corrugated in any form that is used to cushion, separate or fill voids.

Input Rate: The amount of a specific item or part process of consumed in a given amount of time

Insert: A piece of paperboard which is not an integral part of a carton but is used in connection with on carton to perform a special function in separating, holding, or protecting the contents in position as a block, base, cushion, compartment or partition. Such inserts may serve as platforms, steps or frames for displaying the products within a carton.

Insert Molding: The process of molding plastic around preformed metal inserts. This process is compatible with both thermoplastic and thermoset materials.

Insulated Runner (also known as Hot-Runner Mold or Runnerless Molding): A mold in which the runners are insulated from the chilled cavities and are kept hot. Hot-runner molds make parts that have no scrap.

Intaglio:  Any printing process using a recessed image carrier.  Refers to fine art copper plate printing from etchings; commercial copper plate “engraving” used for business cards, stationery, stamps and security printing; and all sheetfed and rotogravure printing.  Generally used in an historical context, and to distinguish gravure from other processes, the term is falling into general disuse in the commercial sector of the industry.

Intensity:  Purity of hue or color tone or the degree of hue as seen by the eye.

Interleave:  To insert separate sheets of paper, etc., between foil, printed paper, or other stacked sheet material to facilitate handling or to prevent blocking or smudging.

Intermediate Temper: Obtained by controlled strain hardening

Interrupted Thread: Container finish thread that has gaps or dis­continuities, the gaps being across the fin or ridge formed at the parting of the container mold. Main purpose of the in­terrupted thread is to avoid possible damage to the interior of the screw closure during its application or use.

Iodine Number:  A number that indicates that relative drying potential of vegetable oils; the higher the number, the faster the drying and oxidation.

Ionomer: Commonly referred to as a Surlyn polymer that comprises repeat units of both electrically neutral repeating units and a fraction of ionized units (usually no more than 15 mole percent) covalently bonded to the polymer backbone as pendant moieties. This means that most ionomers are copolymers of the neutral segments and the ionized units, which usually consist of carboxylic acid groups.

Iridescent:  A term used to indicate the property that is possessed by certain materials of exhibiting prismatic colors.

Iron Blue:  A warm, purplish blue ink, also called Milori Blue.

Iron Perchloride:  Chemical used for copper cylinder etching.  Chemical formula: FeCl3.  Also known as ferric chloride.

Irradiation:  Treated with ultraviolet light or another high-energy ray.

Islands of Automation: Pieces of equipment or systems that are not integrated with the packaging line

ISO: International Organization for Standardization. A group of representatives from other national standard-setting organizations with political links; awards the coveted ISO certification.

Isobar: A line of equal pressure. Any point along an isobar sees the same cavity pressure as any other point along the same isobar.

Isochrone: A line of equal time. Any point along an isochrone is filled at the same time as any other point along the same isochrone.

Isotherm: A line of equal temperature. Any point along an isotherm is at the same temperature as any other point along the same isotherm.

Italic:  The style of letters that slant, in distinction from upright, or roman letters. Used for emphasis within the text.

Izod, Notched, LT: The energy required to break specimens in which there is a v-notch to create an initial stress point but measured at low temperature (minus 40°C).

Izod, Notched, RT: The energy required to break specimens in which there is a v-notched to create an initial stress point.

Izod Impact Strength: A measure of impact strength determined by the difference in energy of a swinging pendulum before and after it breaks a notched specimen held vertically as a cantilever beam.

Izod Impact Test: Test to determine impact strength of a sample by holding a sample bar at one end and broken by striking. Sample specimen can be either notched or unnotched.


Jelling:  The thickening of an ink or other liquid which cannot be reversed by stirring.

Jeroboam: A champagne bottle holding the same amount contained in four ordinary champagne bottles (102-2/5 oz).

Jerry Can: A container of metal or plastic, generally five-gallon capacity, e.g. for gasoline (petrol) and similar liquids.

Jet:  Term used to describe the blackness or intensity of the mass tone of black or near black surfaces.

Jetting: A turbulent flow in the melt caused by an undersized gate or where a thin section rapidly becomes thicker.

Jig: A tool for holding parts of an assembly during the manufacturing process.

JIT: Just in Time

Jog: To align sheets of paper into a compact, even pile.

Joint: The opposite edges of the blank glued, stapled, wire stitched, or taped together to form a box.

Jordan: A machine which mechanically bruises pulp fibers, causing fibrillation and hydration, while serving to produce a more uniform mixture of water and other fibers.

Journals:  The end shafts on which a roll rotates.

JPEG (The Joint Photographic Experts Group): JPEG was formed to create a standard for color and grayscale image compression. JPEG describes a variety of algorithms (rules), each of which is targeted for a specific type of image application. JPEG is the default format for most digital cameras. JPEG 2000 is the latest version. Compressing a JPEG file that is already compressed, will affect quality adversely.

Jug: A bottle, usually of half-gallon or larger capacity, fitted with a handle.

Jumbo Roll:  A roll of web material the outside diameter of which is larger than standard diameter.

Justify:  In composition, to space out lines uniformly to the correct length.


Keg: A small cask, usually of about 40 litres (10 gallons) or less capacity.

Kelvin: The Kelvin scale is a thermodynamic temperature scale (metric).

Kern:  To adjust the lateral space between individual letters.

Key:  To code copy to a dummy by means of symbols, usually letters.  Insertions are sometimes keyed in a like manner.

Keyboard:  The input device to enter information directly into a typesetter, computer, workstation or, as a stand-alone unit, to record on paper or magnetic tape.

Keylines:  In artwork, an outline drawing of finished art to indicate the exact shape, position and size for such elements as halftones, line sketches, etc. Alt:  Lines on mechanical art that show position of photographs or illustrations. Also called a mechanical. This is the guide used in making plates or engraving cylinders, and printing a piece; a diagram of copy and art for reproduction.

Key-Opening Can: A can designed to be opened by winding the lid off around a key, e.g. a sardine can.

Key Plate:  The plate of a set of color plates which carries detail to which the other plates are registered.

K-Factor: A term sometimes used for thermal insulation value or coefficient of thermal conductivity.

Kilobyte (KB):  1,000 bytes.

Kiss Die Cut: To cut the top layer of a pressure sensitive sheet and not the backing.

Kiss Impression: In printing, a very light impression, just enough to produce an image on the paper.

Kiss Register:  See Butt Register

Knife: Hardened steel rule with a sharpened and honed edge to facilitate cutting; also referred to as “cutting rule.”

Knit Lines: When melted material flows together to form a line or lines that may cause weakening or breaking of the component.

Knock Out:  To mask out an image.

Knockout Pin: A pin that ejects a molded article from the mold.

Kraft: Paper or board made from virgin pulp produced by the sulfate process. Natural kraft is unbleached and has a characteristic light brown color; bleached kraft is a sheet having a higher brightness rating than natural kraft.

K.D.F.: A term used by public carriers in referring to boxes cartons other than corrugated when Knocked Down Flat.


Label: A slip of paper, film or foil to be affixed to a container. The label usually carries a graphic design and printed information about the product.

Label Applicator: Machine that applies labels to a package

Label Panel: That portion of the body of a container to which labels are affixed or Decorating imprinted.

Lacquer: A type of coating, applied in liquid form to boxboard, for protective or decorative purposes.

Lag: Specified time increment between the start or completion of an activity and the start of completion of a successor activity

Lake:  An insoluble compound of a dye colorant.  A depression or dishing in the surface of a rubber plate. In Flexographic printing

Lamella:  A blade angle, etched or ground to a thinner gauge than the base thickness of the blade stock.

Laminate:  An adhesive for combining and bonding a combination of films, foils, plastics, papers, or other material in sheet or web form. To cover with film, to bond or glue one surface to another.

Laminated Board: A combination of different kinds of boxboards, films, foils, papers or other materials bonded by adhesives in webs or sheets. May also be designated as “lined board.”

Land (Gate Area): Gate dimension parallel to the direction of melt flow.

Land Area: The area of surfaces of a mold which contact each other when the mold is closed.

Land Dimension: The sealing surface of a glass or plastic bottle.

Land Seal: Also called flat land seal. The Land Seal requires that a flat surface molded into the closure makes contact against the top of the sealing surface (land) of a container. This seal works best when the closure contains a liner material. It is best suited for threaded closures.

Lap:  An area where a color overprints another adjacent color, usually held to a fine line, but which can vary considerably, depending upon the press equipment and the effect created by overprinting two or more colors.

Lap Seal: A seal made with two layers of film overlapping one another.

Laser:  The acronym for Light Amplification by Stimulated Emission of Radiation.  The laser is an intense light beam with very narrow bandwidth that can produce images by electronic impulses from digital media.

Lateral Adjustment:  Movement of the blade toward or away from cylinder; also, parallel blade to cylinder.

Laundry Wraps: All purpose PVC overwrap for use in commercial laundries.

Layout: A rendering of a proposed printed piece, indicating positions for headings, copy, art and borders. May also indicate color treatments.

LDPE or PE (Low Density Polyethylene): A resin base for making film. Porous and somewhat stretchable. Good clarity. Even though LDPE is a relatively strong transparent film with good tensile strength, it does not match the performance of the newer LLDPE. Used mainly for heat sealability and bulk in packaging.

Leaders:  In composition, rows of dashes or dots to guide the eye across the page.  Used in tabular work, programs, tables of contents, etc.

Leading:  (Pronounced ledding) The space, measured in points, between consecutive lines of type. The name derives from the strips of lead historically between lines of hot type in manual typesetting.

Ledger Paper:  A grade of business paper generally used for keeping records; It is subjected to appreciable wear so it requires a high degree of durability and permanence.

Lehr: The long heated oven through which glass containers move on a conveyor belt so gradual cooling will properly anneal and remove stress from glass. Also used to fuse ceramic color onto glass.

Length:  The property of an ink whereby it can be stretched out into a long thread without breaking; long inks exhibit good flow characteristics.

Letter Check: An edge or side defect. A small check which appears in the lettering.

Letterpress Printing: The printing process by which ink is transferred from the raised portions of printing plates or type to board.

Letter Spacing:  The spacing of letters for proper optical balance.  Also adding or subtracting a small amount of space between each letter or character to adjust (justify) the length of a line of copy.

Leveling Action:  The ability of a plating solution to produce a surface smoother than the substrate of base metal.

Lid: A separate top or cover of a can, box, or container. May be hinged or otherwise attached to the body of the container.

Lid Sealing Compound: Flowed-in pliable material which forms a rubber-like (often a latex) gasket to seal the joints of metal cans and the seal between bottles and their closures.

Light, UV Stabilizers and Absorbers: These additives increase the ability of the material to withstand the negative effects of light and UV exposure, thus increasing the service life of the material.

Light Bottom: A bottom defect. A localized thin area in the bottom of the container.

Light Fastness: Light fastness is the ability of the paperboard to remain white despite exposure to light. Bleached chemical pulp fibers make the paperboard light stable for an extended period of time. The patented coating formula provides outstanding light fastness, further extending the product shelf life.

Light Reflection:  The light, striking an object, which is turned back. The opposite of absorption.

Light Seam: An edge or side defect. A defect characterized by thin spots in the side of the ware.

Light Stability:  A measure of the ability of a pigment, dye, or other colorant, to retain its original color and physical properties upon exposure to sun or other light. Either alone or when incorporated into plastics, paints, inks and other colored surfaces. Ability of a plastic or other organic film or surface to withstand the deteriorating effect of exposure to sun or other light independently of the stability of any pigmentation it contains.

Lignin: Lignin is the substance that is removed from the wood in the pulping processes in order to extract the virgin fibers.

Linear Low Density Polyethylene (LLDPE): Stronger than low density. Resistant to punctures and tears, non-porous, and stretchable.

Linear Mold Shrinkage: The difference between the size of the part and the size of the mold cavity. Values given are often the average of a range.

Linear Thermal Expansion: The fractional change in length of a material for a unit change in temperature.

Line Copy: Any monochrome copy suitable for reproduction without using a halftone screen.

Line Cut: Engraving made from line copy.

Lined Chipboard: A broad class of board composed of a filler material sandwiched between at least one liner but possibly two liner boards. There are many different types of lined chipboards, a few are discussed below.

  • Double White-Lined (DWL) – has two white liner boards that cover the gray recycled filler layer(s).

  • Single White-Lined (SWL) – has a top layer of high quality new or recycled pulp with a bottom layer of lower quality recycled filler board. The finished board ranges from light gray to brown.

Line Films:  Photographic film that converts all tones of gray to just black or white granular solids.

Line Growth: The growth of a printed line as a result of pressure between the printing plate and the substrate.

Liner: Packaging board used as a surface layer on corrugated board.

Linerboard: The grade of paperboard used for the exterior facings of corrugated board. Used in the manufacture of corrugated and solid fiber shipping containers, linerboard is made predominantly on a Fourdrinier machine. It is used by the packaging industry as a facing material for containers.

Line Screen:  A number used to express the fineness of a halftone screen, ranging from 25 to 300 or more lines per linear inch.  The number refers to the number of dots such a screen is capable of producing in a single row exactly one inch long.

Lines Per Inch: The number of rows of dots per inch in a halftone.

Linetone: A form of halftone composed of lines instead of dots.

Lint: Loose fibers.

Linting: See Picking

Lip: A bag where one side is longer than the other, allowing the bag to be opened more easily.

Lip of the Blade: Wiping edge of a doctor blade.

Liquid Injection Molding (LIM): The process that involves an integrated system for proportioning, mixing, and dispensing two component liquid resin formulations and directly injecting the resultant mix into a mold which is clamped under pressure.

Lithography: A printing process using plates whose printing surfaces are partially water repellent and partially ink (oil) repellent. The plates are made of flexible sheets of metal, such as zinc or aluminum, or of two metals as in bimetal plates. Plates are photographically imposed, chemically etched and run on either sheet-fed or roll-fed presses. The term lithography is often shortened to “litho.”

Litho-Laminating: The process of laminating litho pre-printed sheets to a single-face corrugated structure, forming a double-face structure.

Livering:  An irreversible increase in the body of inks as a result of gelation or chemical change during storage.

Load:  The total weight supported by the force of a roll.  It usually is expressed in pounds per linear inch, abbreviated PLI.

Loading Marks: A general defect. Fine vertical laps on surfaces.

Local Area Network (LAN):  In electronic publishing, the linking of workstations, storage units (file servers) and print-out devices (print servers).

Locking Ring: Metal closing ring around the rim of a full-removable-head container intended to retain the cover and form a seal. The ring is a circular modified “V” or “U” section channel, the ends of which are drawn together by means of a bolt and the periphery thus shortened, to develop the closure.

Locking Tabs: A design feature that holds the package together during construction.

Log:  A master roll of paper from which finished rolls are slitted, spliced and rewound for shipment to the printer.

Logotype (or logo):  The name of a company or product in a special design used as a trademark in advertising.

Long Ink:  An ink that has good flow on ink rollers.  If the ink is too long, it breaks up into filaments on the press, and causes flying as in a newspaper printing.

Long Neck: A neck defect. A neck which has been stretched longer than that specified.

Lost-Time Accident (LTA) Frequency: measure of the number of disabling injuries per year

Loupe:  A magnifying glass used to review a printed image, plate and position film.

Low Temperature Flexibility: The ability of a plastic to be bent without fracture at reduced temperatures.

Lpi: Acronym for lines per inch. Used as a measurement of resolution or halftone screening.

L-Sealer: A term used to describe equipment where the seal area is in the shape of a “L”.

Lubricant: Internal lubricants promote resin flow without affecting the fusion properties of a compound. External lubricants promote release from metals, enabling the smooth flow of melt over die surfaces.  

Lug: (1) A box, basket or other container suitable for handling or shipping fruit or vegetables; usually refers to the relatively shallow, nailed wooden box. Also lug-box. (2) A projection on a part or a package used for fastening or to ob­tain a fit between two parts. (3) A metal fasten­er used for securing the top or bottom heads of a fiber drum, steeI drum, or metal pail to the side-wall. (4) Extensions around the circumference of a lid which are crimped down to hold the lid securely in place against the body of the container.

Lug Cap: A metal or plastic closure designed to be secured by engaging lugs on the neck or finish of a container e.g. twist-off caps.

Lug Cover: A cover for metal drum or pail, with extensions around the circumference that are bent down to hold the cover securely in place against the container body.

Lug Finish: Also called Lug/Twist. A glass container finish identified by intermittent horizontal tapering protruding ridges of glass that permit the specially shaped edges of the closure to slide between the protruding lugs and fasten securely with a partial turn. These lug finishes have the GPI designations in the 2000 series.


Machinability:The ability to form and seal on overwrapping equipment.

Machine: A system of components arranged to transmit motion and energy in predetermined fashion

Machine Coated: Paper that is coated on one or two sides on a paper machine.

Machine Direction (MD): The direction the film is manufactured and the direction it moves through the sealing equipment.

Machine Downtime: total amount of time a given machine in the line has stopped production during the run period.

Machine Erect: A package that is fully or partially erected by a machine.

Machine Finish: The finish applied on the paper machine.  The finish is commonly referred to as M.F.

Machine Glazed: (M.G.) The finish produced in glaze on the wire side of a sheet as it is passed in contact over a single, large diameter, steam-heated cylinder on the Yankee Machine.  The finish is commonly referred to as M.G.

Machine Set: When type is set by using a keyboard on a machine instead of setting each character by hand into a typestick.

Machine Shot Capacity: Refers to the maximum volume of thermoplastic resin which can be displaced or injected by the injection ram in a single stroke.

Machine Tape: Quick release tape that can seal the top and/or bottom of a package

Machine Wire: The continuous copper or bronze wire which is the traveling surface upon which the web of paper is formed. It is usually referred to as the “wire”.

Magenta: Hue of a subtractive primary and a four-color process ink. It reflects or transmits blue and red light and absorbs green light.

Magenta Screen: A dyed contact screen that is used for making halftones.

Magnetic Storage:  Any disc, film, tape, drum, or core that is used to store digital information.

Magnum: A glass bottle, used occasionally for sparkling wines, having a capacity of two-fifths U.S. gallon. Some foreign magnums vary in capacity.

Maintenance: Ensuring that all machinery and systems are in operable condition at all times

Makeover:  In platemaking, a plate which is remade.

Make-Ready: General preparatory operations prior to the actual production of printing, or cutting and creasing. It usually involves the adjustment of the impression by overlaying or underlaying the printing plates; the cutting of the female part of the die. Also used in connection with finishing machines such as gluer, waxer, windower.

Makeup:  In composition, the arrangement of lines of type and illustrations into sections or pages of proper length.

Mandrel: A round object against which material can be forged or shaped.

Manila Board: Boxboard made principally from mechanically ground wood pulp used largely for packaging foods. It has a light straw color and a suitable surface for printing.

Manipulation:  Adjustment to the doctor blade required to get optimum results.

Manufacturer’s Joint: Where the two ends of a box blank must be fastened together with tape, staples or glue.

Manufacturing Costs: Raw and packaging materials, manufacturing expenses, processing costs, and variations.

Marginal Words:  Call outs for directions on various parts of a business form.

Mar Resistance: The resistance of glossy plastic surfaces to abrasive action.

Mask:  In color separation photography, an intermediate photographic negative or positive used in color correction.  In offset lithography, opaque material used to protect open or selected areas of a printing plate during exposure. Alt: Blocking light from reaching parts of a printing plate.

Master:  A plate for a duplicating machine.

Masterbatch: A concentration of a substance (an additive, pigment, filler, etc.) in a base polymer.

Material Safety Data Sheets (MSDS): Documentation regarding the toxicity or hazards associated with contact with some substances. The manufacturer of the plastic prepares these data sheets.

Matrix: A mold in which type is cast in linecasting machines.  In stereotyping, the paper mold or mat made from a type form.

Matte Finish: Dull paper finish without gloss or lustre.

Maximum Angle of Wipe:  Flattest wipe obtainable.

Maximum Displacement: The maximum amount of overall change in position of an object over time.

Maximum Stretch: The ability of a film to stretch as far as it can without tearing.

MDPE: Medium density, (0.934-0.95) polyethylene. Has higher stiffness, higher melting point and better water vapor barrier properties than low density PE.

Mealiness:  See Snow Flaking, specifically in middle tones.

Mechanical:  A term for a camera-ready paste up of artwork.  It includes type, photos, line art, etc., all on one piece of artboard.

Mechanical Property: Properties of plastics which are classified as mechanical include abrasion resistance, creep, ductility, friction resistance, elasticity, hardness, impact resistance, stiffness and strength.

Mechanical Pulp: Mechanically processed fibers are harder and more rigid than chemically processed fibers. Paperboard made solely from mechanical pulp is relatively weak, but stiff and bulky with high dimensional stability.

Mechanical Separation:  Mechanical art overlay; one is created for each color to be printed.

Mechanism: A system of components arranged to transmit motion in a predetermined fashion

Medium: The paperboard used to make the fluted layer of corrugated board.

Melt Flow Rate: A measure of the molten viscosity of a polymer determined by the weight of the polymer extruded through an orifice under specified conditions of pressure and temperature. Condition specifics are dependent upon the type of polymer being tested.

Melt Index: The amount of a thermoplastic resin, measured in grams, which can be forced through a specified orifice within ten minutes when subjected to a specified force. (ASTM D-1238)

Melt Strength: The strength of plastic while in the molten state. This is a pertinent factor in extrusion, blow molding and drawing of molten resin from a die.  

Memory: The ability of a film to maintain its characteristics after shrinking.

Metal Can: A rigid metal container made of steel, tinplate, aluminum or other metal.

Metallic Ink: Bronze or aluminum powder suspended in an appropriate vehicle and applied as a printing ink to produce designs with a metallic luster on the surface being printed. In addition to natural metals, lustrous tints of other colors may be produced by adding small amounts of transparent color to aluminum inks.

Metallizing: Applying a thin coating of metal, usually aluminum, by vacuum deposition onto a non-metallic film or paper surface in a vacuum chamber.

Metallocene: Thinner and stronger than low density polyethylene. Puncture resistant.

Metamerism:  A condition when colors match under one light source, but do not match under another light source.

Methyl Ethyl Ketone (MEK):  A relatively fast-drying organic solvent of the ketone family.  Highly flammable.  Good solvent for nitrocellulose and vinyl lacquers.  Small amounts will swell Buna-N plates, large amounts will swell natural rubber.  Boiling point 175 degrees F, flash point 24 degrees F.

MET-OPP: Metallised OPP film. It has all the positive properties of OPP film, plus much improved oxygen and water vapor barrier properties, (but not as good as MET-PET).

MET-PET: Metallised PET film. It has all the positive properties of PET film, plus improved oxygen and water vapor barrier properties. However, it is not transparent. see also VMPET.

Metric conversions:

1 kilogram (kg) = 2.2046 pounds

1 meter = 39.37 inches = 1.0936 yards

1 pound = 0.4536 kilograms

1 mile = 1.6094 kilometers

1 short ton = 2000 pounds

1 yard = 0.9144 meter

1 kilometer = 0.6237 miles

1mil = 1/1000 of an inch = .001

1 mil = 25.4 microns

1 micron = one millionth of a meter

1 inch = 25.4 mm = 2.54 cm

100 gauge = 1 mil

80 gauge = 8/10 mil = .0008 inches

Mezzotint: 1) An early copper plate-engraving method that created the impression of tonal variation through patterns of dots cut with tools. Used only in fine art engraving.  2) Any of a variety of special effect screens used to convert line art into fine patterns without the use of halftone dots.

Microdots: A dot, not visible “to the naked eye”, that is used in the place of Eye-marks. Microdots are not always available to be used.

Micrometer:  Instrument used to measure the thickness of different papers.

Middletones: The tonal range between highlights and shadows of a photograph or reproduction.

Middle Tones:  The tones in a photograph that are approximately half as dark as the shadow area.

Migration (also know as Bloom): An undesirable cloudy effect or whitish powdery deposit on the surface of a plastic, caused by the exudation of a compounding ingredient such as a lubricant, stabilizer pigment, plasticizer, etc.

Mil: Thickness of material: The higher the mil, the stronger the material. (1/1000 inch = 1 mil)

Mileage:  The surface area covered by a given quantity of ink or coating material.

Mill Roll:  Roll of paper, film, or foil as received by converter from mill.

Mineral Reinforcements: Inorganic substances used as filler for plastics. Some common examples are: clay, mica, talc.

Mineral Spirits:  Hydrocarbon petroleum distillates having a boiling range of approximately 300-350 degrees F.

Mini-Flute: Term used for corrugated boards with small flute heights. Boards include E, F, G, and N flute. Refer to “Small Flute Paperboard.”

Minimum Angle of Wipe:  Sharpest (steepest) wipe obtainable.

Minimum Specifications: The minimum values, usually of mechanical properties, that a compound must meet by Quality Assurance prior to shipment.

Misregister: See Register

Misting:  A mist or fog of tiny ink droplets thrown off the press by the rollers.

Mist Lined Chipboard: Colored manila top liner boxboard containing some long black fibers to give a mist effect on bending chipboard. Also referred to as “Mist Grey Chipboard.”

Modulus: Derived from the Latin word meaning “small measure”, modulus is the ratio of stress to strain in the linear region of the s-e curve.

Modulus in Compression: The ratio of compressive stress to strain within elastic limits of the material.

Modulus in Flexure: The ratio of the flexure stress to strain, within elastic limits of the material.

Modulus in Shear: The ratio of shear stress to strain within elastic limits of the material.

Modulus of Elasticity: The ratio of stress to corresponding strain below the proportional limit of a material in tensile testing.

Modulus of Resilience: The energy that can be absorbed, per unit volume, without creating a permanent distortion.

Moire:  In color process printing, the undesirable screen pattern caused by incorrect screen angles of overprinting halftones. Alt:  Occurs when screen angles are wrong, causing odd patterns in photograph reproduction.

Moisture Absorption: The pick-up of moisture from the environment by a material.

Moisture Content: The amount of water in boxboard expressed as a percent of factory paper weight of the test sample.

Moistureproof: A coating, extrusion or laminated barrier which resists the passage of moisture through a package.

Moisture Vapor Transmission Rate (MVTR): The mass of water vapor transmitted through paperboard when exposed to various humidity levels. Also referred to as “moisture vapor transfer rate” or “water vapor transmission/transfer rate” (WVTR).

Mold (n): A hollow form or matrix into which a plastic material is placed, imparting to the material its final shape as a finished article.

Mold (v): To impart shape to a plastic mass by means of a confining cavity or matrix.

Moldability: The characteristics of being easy to mold without rupturing or developing flaws due to movement of the polymer during gelation.

Mold Changer: An automated device for removing one mold from a machine and replacing it with another mold.

Mold Frame: A series of steel plates which contain mold components, including cavities, cores, runner system, cooling system, ejection system, etc.

Molding Cycle: The period of time occupied by the complete sequence of operations on a molding press needed for the production of one set of molded articles.

Molding Press: A platen press in which matrices or rubber plates are formed.

Molding Pressure: The pressure applied to the ram of an injection machine or press to force the softened plastic completely to fill the mold cavities.

Molding Sensitivity: The variability of the pressure to fill the cavity and temperature of the melt at the part as influenced by changes in injection time and barrel melt temperature.

Molding Window: The range of molding conditions under which a part can be successfully molded.

Mold Number: The number assigned to each mold or set of molds for identification purposes, usually placed in that part of the container mold that forms the base of the container.

Mold Release: In injection molding, a lubricant used to coat the surface of the mold to enhance ejection of the molded article or prevent it from sticking to the tool.

Mold Release Problems: Excess use of mold release may leave parts oily and weaken the material.

Mold Seam: A vertical line formed at the point of contact of the mold halves. The prominence of the line depends on the accuracy with which the mating mold halves are matched. Also known as parting line.

Mold Temperature: The temperature at which the mold is maintained. Often the most important benefit of raising mold temperature is that it allows a slower injection rate without the plastic getting too cold.

Molecular Weight: The sum of the atomic weights of all atoms in a molecule. Especially in plastics, an average molecular weight is reported.

Molecule: The smallest unit quantity of matter which can exist by itself and retain all of the properties of the original substance.

Molletone: In offset lithography, a thick cotton fabric similar to flannel used on the dampening rollers of a press.

Monitor Calibration: A simple method that starts with the adjustment of monitor settings in terms of brightness and contrast.

Monitoring: Following the process of the project

Mono-Layer Film: A single layer film extruded from one or a blend of raw materials.

Monomer: A relatively simple molecular structure, usually of low molecular weight, which can react to form a polymer by combination with itself or with other molecules and energy.

Montage: In artwork, several photographs combined to form a composite illustration.

Mottle: The spotty or uneven appearance of printing, mostly in solid areas. Also known as variable print impression or lack of uniformity in print appearance, mottle can arise from one of the following possible causes:

  • Non-uniformities in the base sheet of the paperboard

  • To prevent mottle, a paperboard with high and uniform quality of both the baseboard and the coating is required

  • Variable absorbency of the ink from the first printing unit onto the sheet causing variations at the second blanket, which then back traps in a variable way onto the succeeding sheet (back trap mottle)

  • Due to the variable absorbency of water into the sheet, ink at subsequent sheets may be repelled (water induced mottle)

  • Excessive ink emulsification

  • Local variation in the surface finishing

Mounting: The process of affixing plates on a cylinder or base in proper position to register color-to-color, as well as to the wrapper or bag to be printed.

Mounting and Proofing Machine:  Device for accurately positioning rubber plates to the plate cylinder and for obtaining proofs for register and impression off the press.

Moving Platen: The platen of an injection molding machine that is moved by a hydraulic ram or mechanical toggle.

Mullen Burst Test: Measures the force required to rupture linerboard when under pressure; related to a box’s ability to withstand external and internal forces.

Mullen Test: Measurement of bursting strength of paper and paperboard, in pounds per square inch. A relatively simple machine, either motor-driven or hand-operated, applies increasing pressure to one square inch of the sample until it ruptures.

Multi-Cavity: Mold A mold with more than one cavity impressions. Therefore, the mold produces two or more bottles per molding cycle.

Multicolor Overprinting: The technique of overprinting a given number of transparent colors to produce additional colors, without using halftones. Orange, green, purple, and brown may be produced by overprinting cyan, magenta and yellow, resulting in a total of seven colors from three.

Multidirectional Flow: Flow direction changes during filling, resulting in orientation in different directions. Can cause flow marks, stresses and warping.

Multilayer Film: A film comprised of more than one layer of similar or different polymers.

Multi-Ply Paperboard: The multi-ply technique involves bringing together several layers of pulp in the wet state. The big advantage is that this construction allows us to optimize the paperboard features by using a combination of different types of pulp and fibers from different wood species. As both stiffness and strength are important, a compromise is needed to achieve the best result. The strength, flexibility, and consolidation behavior of chemically processed fibers result in well formed, dense, strong paperboard products. Mechanically processed fibers have the opposite characteristics, resulting in open, bulky, and weak–but very stiff–products. By using different types of pulp in different layers and combining this with various sheet constructions and coatings, the multi-ply technique allows us to tailor the paperboard features to suit many different market requirements. To achieve a smooth surface, short fibers are used in the surface layers. To achieve elasticity, strength, and the sense of quality of a dense paperboard, a greater proportion of long fibers is used in the middle layers. It is also possible to use the same fibers for every layer and apply different preparation treatments to them.

Multi-Shot Molding: The injection of two or three materials, in sequence, into a single mold during a single molding cycle. The injection molding machine is equipped with two or three plasticators.

MVTR: Moisture vapor transmission rate, usually measured at 100% relative humidity, expressed in grams/100 square inches/24 hours, (or grams/square meter/24 Hrs.) See WVTR.

Mylar:  A polyester film which exhibits exceptional mechanical strength and dimensional stability. Common substrate used in flexographic film printing.


Nanometer: A unit of measurement in which wavelengths of light and other radiant energy are expressed. One nanometer is one-billionth of a meter.

Naphthas: Aliphatic hydrocarbon solvent derived from petroleum such as hexane, VM&P naphtha, etc.  Characterized by low K.B. values.  Will swell natural or butyl rubber, have slight effect on Buna-n or Neoprene.

Narrow Mouth: A container having an opening roughly one half the diameter of the container or smaller.

Natural Drying Time:  The amount of time taken from the last printing unit until elevated web temperature begins.

Natural Frequency: Frequency of vibration of a system after an initial force is applied.

Naturally Balanced Runner System: Each succession of runner is identical to the runners in the same succession in all other flows in the mold.

Neck: The narrow upper part of a container between the shoulder and the opening. The nozzle containing the dispensing orifice of a collapsible tube.

Neck Bead: Usually a protruding circle on the neck of the bottle.

Neck Down: The narrowing tendency of stretch film when being stretched or pulled.

Necked-In Container: A container, the body of which is abruptly reduced in diameter at top or bot­tom end to provide for stacking and to economize on the size/cost of end components.

Neck Insert: Part of the mold assembly which forms the neck and finish. Also called the neck ring.

Neck Ring Seams: A finish defect. Seams which have a fin of glass around the parting line between the finish and the neck of the bottle.

Negative: In photography, film containing an image in which the values of the original are reversed, so that the dark areas appear light and vice versa.  (See positive) Alt:  The image on film that makes the white areas of originals black and black areas white.

Neoprene: A synthetic chlorinated butadiene rubber used in making flexo-rollers resistant to alcohols, cellosolve, water, aliphatic hydrocarbons and to a limited extent esters (acetates).  Not resistant to aromatic hydrocarbons.

Nested: When three or more different sizes of an article are placed within the next larger size, or when three or more of the same articles are placed one within the other so that each upper article does not project above the next lower article by more than one-third of its height.

Nested Solid: When three or more of the same articles are placed one within or upon the other so that the outer side surfaces of the one above will be in contact with the inner surfaces of the one below and so that each upper article will not project above the next lower article by more than one-fourth of an inch.

Nesting Containers: Containers made with sloping sidewalls so they can be nested in each other when empty to conserve space.

Nest Plate: A retainer plate in the mold with a depressed area for cavity blocks.

Neutral Sodium Sulfite Process:  A chemical pulping method adaptable to many tree species and operable with minimal environmental problems.

Newsprint:  Paper made mostly from groundwood pulp and small amounts of chemical pulp; used for printing newspapers.

News Vat Lined Chipboard: A combination boxboard made on a cylinder machine from chip and news liner waste newspaper stock.

Nicks: When a sheet of paperboard is die cut, the cut blanks remain linked to each other by uncut parts (nicks) to facilitate easy handling in the subsequent conversion operations.

Nip:  Line of contact between two rolls.

Nitrocellulose:  A film formerly widely used in flexographic and gravure inks; nitrated cellulose.  See Pyroxylene.

Nodule:  A small lump of rounded or irregular shape, such as a chrome projection on an anilox roll, needing additional polishing for removal.

Non-Fill (also known as Short Shot): Failure to completely fill the mold or cavities of the mold. Edges may appear melted.

Non-Fogging Film:  Film that does not become cloudy from moisture condensation caused by temperature and humidity changes.

Non-Impact Printer:  An electronic device like a copier, laser or ink-jet printer that creates images on a surface without contacting it.

Non-Impact Printer: An electronic device such as a copier, laser, or inkjet printer that creates images on a surface without contacting it.

Non-Increment Press:  A flexographic press capable of printing infinite variable repeats, not dependent on standard gear pitch increments.

Non-Reproducing Blue:  A blue color the camera cannot see.  Used in marking up artwork.

Non-Return Valve: Screw tip that allows for material to flow in one direction and closes to prevent back flow and inject material into the mold (check valve).

Non-Reusable Container (NRC): (1) Mandatory embossing on the bottom of steel shipping containers indicating an un-reusable container. (2) Also used to indicate any non-reusable container. (3) A container, often required to be marked NRC, whose re-use is restricted by one or more regulatory agency.

Non-Scratch:  Inks that have high abrasion and mar-resistance when dry.

Nonvolatile:  That portion of a material that does not evaporate at ordinary temperatures.

No-Screen Exposure:  See bump exposure.

Notch Sensitivity: The extent to which the sensitivity of a material to fracture is increased by the presence of a surface notch or sudden change in section.

Nozzle: Hollow metal hose screwed into the extrusion end of the heating cylinder of an injection machine. Designed to form a seal under pressure between the cylinder and the mold.

Nucleating Agent: Additive used in a polymer to increase crystallization rate by providing additional sites for crystal growth (i.e. Talc). This results in faster cycle time.

Numbered Package: A package authorized for use in the shipment of specific articles, identified by an assigned number and described in detail in special sections of the carrier classifications. See also: Package

Nutrition Facts: The area of information on a food product. The best and most up-to-date information can be found on

Nylon: Polyamide resins, with very high melting points, excellent clarity and stiffness. Two types are used for films – nylon-6 and nylon-66. The latter has much higher melt temperature, and better temperature resistance, but the former is easier to process and less expensive. Both have good oxygen and aroma barrier properties, but they are poor barriers to water vapor. Nylon films can be cast or oriented.


Object oriented:  An approach in drawing and layout programs that treats graphics as line and arc segments rather than individual dots. Also called vector oriented.

Oblong:  A booklet or catalog, bound on the shorter dimension.

OCC: Old corrugated containers (important grade of recycled fibers).

Occurrences: Any anomaly or action in the packaging process that actually stops that process

OD:  Outside diameter of a part, generally a cylinder or roll.  Outside dimensions of a container, package, or part.

Odorants and Deodorants: Odorants are used to add odor to materials, usually for safety reasons. Deodorants neutralize odors.  

Off Balance Weight:  Weight added to the doctor blade by its mechanism.

Off-Gage Finish: A finish defect. A finish which is usually oval-shaped and which may be pinched or flattened in one or more places. Also call “out-of-round”.

Off Loading:  Relieving the intensive amount of data processing associated with a specific application (i.e., graphics) from the CPU, by performing those calculations in a dedicated or specialized processor.

Off-Press Proofs:  Proofs made by photomechanical or digital means in less time and at lower cost than press proofs.

Offset:  The transfer of improperly or incompletely dried ink from the face of a print to the back of the stock on top of it in the roll or pile.  The accidental transfer of ink from the idler or other rolls in a press to the web.

Offset Core:  A core in a substrate roll that protrudes from the roll.

Offset Finish: A finish defect. A finish which is formed with the two halves of the mold shifted out of alignment, either vertically or horizontally.

Offset Gravure: Printing gravure by the offset principle. Generally done on a flexographic press by converting the anilox roller to a gravure image cylinder and covering the plate cylinder with a solid rubber plate.

Offset Lithography: When offset is used in combination with the lithographic printing process, which is based on the repulsion of oil and water, a flat image carrier on which the image to be printed obtains ink from ink rollers, while the non-printing area attracts a water-based film, keeping the non-printing areas ink-free.

Offset Paper:  Term for uncoated book paper.

Offset Powder: A powder applied to the surface of a litho-printed sheets to prevent the ink from transferring (offsetting) to the surface of the adjacent sheets as the sheets are stacked off the delivery end of the printing press.

Offset Printing: The process of printing by indirect image transfer, especially by using a metal or paper plate to ink a smooth rubber cylinder that transfers the ink to the paper.

Offsetting:  See set-off.  In printing, the process of using an intermediate blanket cylinder to transfer an image from the image carrier to the substrate.  Short for offset lithography. Alt:  Also, an unpleasant happening when the images of freshly printed sheets transfer images to each other.

Olefin Polymers: FDA Regulations concerning.

Oleophilic:  Oil receptive.  Literally – loving oil.  A term that may be used in food packaging.

One Stop Shop: the ability to acquire products from the same supplier instead of going to a mass of suppliers.

Opacity:  The amount of show-through on a printed sheet.  The more opacity or the thicker the paper the less show-through. The thicker or heavier the paper, the higher the cost. Alt:  That property of paper which minimizes the show-through of printing from the back side or the next sheet.

Opaque: In photo engraving and offset lithography, to paint out areas on a negative not wanted on the plate.

Opaque Ink: An ink that conceals all color beneath it.

Operating Side:  That side of a flexographic press on which the printing unit adjustments are located; opposite of driving side or gear side.

OPP: Oriented PP (polypropylene) film. A stiff, high clarity film, but not heat sealable. Usually combined with other films, (such as LDPE) for heat sealability. Can be coated with PVDC (polyvinylidene chloride), or metallised for much improved barrier properties.

Optical Distortion:  Change in appearance of objects viewed through a transparent material, adding certain defects such as waviness of surface, etc.

Optics: The visual properties of a film. Examples; an anti-fog shrink film providing clear presentation in refrigerator and freezer applications.

Orange Peel: An uneven surface somewhat resembling an orange peel.

Organosol:  A suspension of particles in an organic solvent, usually made with vinyl resins, solvents, and plasticizers.

Orientation:  The arrangement of the molecules of the melt. If the molecules are orientated, they are aligned with each other; if non-orientated they are not in alignment. In general, orientated material shrinks more than non-orientated material.

Orienters: Machinery that moves the packages by the use of different methods in order to have them in the right direction.

Orifice: The opening in a container through which product is dispensed.

Orthochromatic:  Photographic surfaces insensitive to red, but sensitive to ultraviolet, blue, green and yellow rays.

Oscillation:  Side-to-side motion of the doctor blade mechanism over the cylinder.

OTR: Oxygen Transmission Rate. OTR of plastic materials varies considerably with humidity, therefore it needs to be specified. Standard conditions of testing are 0, 60 or 100% relative humidity. Units are cc./100 square inches/24 hours, (or cc/square meter/24 Hrs.) (cc = cubic centimeters).

Outfeed Conveyor: conveys the package from the sealer to shipping.

Outline Halftone:  Removing the background of a picture or silhouetting an image in a picture.

Out-of-Shape Ware: A general defect. Ware which is tilted to one side or which is bulged, sunken-in, or mis-shapen.

Output: exact quantity of quality packaged produced in a package run cycle as required by the customer and shipped to the customer.

Output Rate: the number of items leaving a machine in a given amount of time.

Oval: A particular shape. A container which has an elliptical cross section perpendicular to the major axis.

Overhang Cover:  A cover larger in size than the page it encloses.

Overlap: A design feature wherein the top and/or bottom flaps of a box do not butt, but extend one over the other. The amount of overlap is measured from flap edge to flap edge.

Overlay: A transparent covering over the copy where color breaks, instructions, or corrections are marked.

Overlay Proof: A hard copy color proof produced with four dyed or pigmented overlay films.

Over Molding: A process in which a mold cavity is first partially filled with one plastic and then a second shot is injected to encapsulate the first shot.

Overpack: Melt will fill the easiest flow path first, and will continue to pack this area while material reaches the other areas. This is a cause of warping created by unbalanced flow.

Overpress: A finish defect. A finish which has excessive glass projecting upward from the inside edge of the finish. See also “wire edge” defect.

Overprint: To print additional material, such as a varnish or another color, on a previously printed sheet.

Overprinting: Double printing; printing over an area that already has been printed.

Overrun: Additional copies printed in excess of the specified quantity.

Overtone: The modifying hue or tone of a color.

Overwrap: A plain or printed sheet of paper, foil or flexible film applied over a filled carton or tray for decorative or protective purposes.

Oxygen Index: A flammability test based on the principle that a certain volumetric concentration of oxygen is necessary to maintain combustion of a specimen after it has been ignited.


Package: (1) Noun – A sealed wrapping or box containing either a retail-sale quantity of a product (consumer package) or a product of a number of items or smaller packages in transport quantities, for transportation and storage (transport package). (2) Verb – To put a product into a package or to make a package around a product.

Package Testing Service: Evaluation of basic packaging materials such as corrugated, paper and paperboard, foams, plastics, and films. Tests include shock transmission, vibration analysis, tear, creep, burst test, altitude testing, etc.

Packaging, Hazardous Material: United Nations certified containers for the domestic and international transportation of hazardous materials by air, ground and water.

Packaging Component: A packaging component is any stand alone element of a primary or secondary package such as a bottle cap or a protective sleeve, or any stand alone element of transport packaging such as a pallet or strapping, and includes labels, adhesives, inks and/or coatings used on the component.

Packaging Line: An assemblance of specialty-function machinery or systems and/or manual workstations from depalletizing to palletizing integrated together to carry out a process in which a given product is combined, inspected, and transported with inputs or media

Packaging Process: The combined execution of specialty-function machinery or systems and/or manual workstations in order to carry out a process in which a given product is combined and/or assembled with inputs or media.

Packaging Services: Packaging services include package concept, design, drawings, models and prototypes, decorating options, estimated costs, and coordination of physical and time factors.

Packer: A line of bottles used primarily in the pharmaceutical industry. The bottles have large finishes with respect to bottle size, making bottles easy to pack.

Packing: In printing presses, a material, usually special paper, used to underlay the image or impression cylinder in letterpress or the plate or blanket in lithography. Used to ensure proper squeeze or pressure for printing.

Pack Station: A side belt driven tape sealer that allows the package to be held in position so the operator can load it.

Pad: A corrugated or fiberboard sheet used to separate and protect layers of product during shipping.

Page Buffering: The ability to spool an entire image to disk and print at one time for uninterrupted flow.

Page Description Language (PDL): In digital prepress, a computer language designed for describing how type and graphic elements should be produced by output devices. PostScript is the most commonly used PDL in printing.

Pail: A container of circular cross-section, generally a cylindrical or truncated cone in shape, fitted with a handle. May be made of metal, reinforced fiber or plastic.

Palette:  The collection of colors or shade available to a graphic system or program.

Pallet: A low, portable platform of wood, metal, plastic, or fiberboard which facilitates the handling, storage, and transportation of materials as a unit.

Palletizer: A machine that forms, dismantles or secures pallets and other loading units. Can be either conventional (fixed) or robotic (flexible).

Palletizing: Securing and placing containers on pallets into one single load for shipment.

Pallet Wrap Film: Thin film applied to a palletized load to prevent movement during shipping.

Pallet Wrapper: A machine that is equipped with a turntable that rotates the pallet as film is applied.

Panchromatic:  Photographic film sensitive to all visible colors.

Panel: A face, side, top or bottom of a folding carton.

Panel Check: An edge or side defect. A check characterized by deep V-shaped cracks appearing on the edge or side.

Paperboard: A general term describing a sheet of fibrous material usually made on a cylinder or fourdrinier machine from either virgin wood fiber (pulp), recycled paper stock (old newspapers, old corrugated), or a combination of these fiber sources. Paperboard differs from paper in that it is heavier, thicker, and more rigid. The two general classifications of paperboard are containerboard, which is used principally in making corrugated and solid fiber boxes; and boxboard, the bending grades of which are used in the manufacturer of folding cartons.

Paper Caliper: The thickness of a paper stock measured in millimeters.

Parison: Also called a “gob”, “pattern” or “blank”. A hollow plastic tube from which a container is blown in extrusion blow molding. In injection blow molding, it is the plastic shape formed by the core rod and parison mold that is transferred into the blow cavity for forming the final shape. Parison can also refer to the preliminary shaped red hot glass that hangs from the neck rings as the blank molds open.

Particulate Matter: Unwanted foreign material which may become attached to or enveloped with a “clean” product. May be dust, debris, hair, or other particles. Generally 0.5 um or larger. May be airborne or “gross”.

Parting Agent: A lubricant, often wax, used to coat a mold cavity to prevent the molded piece from sticking to it and facilitate its removal from the mold. Also called release agent.

Parting Line: The slight horizontal ridge formed by a surplus of glass blown into a worn crevice or joint between two parts of the mold equipment. These lines may occur on various areas of the container, such as between the neck ring and the plunger tip or guide ring, between the neck ring and blank or mold, and between the mold and bottom plate. The vertical line formed by the joint between two halves of the same mold part is called a “seam”.

Partition: Any wall or panel that separates cells, sections or units.

Paste Dryer: In ink-making, a type of dryer. Usually a combination of drying compounds.

Patent Coated Boxboard: A combination white vat lined board made on a cylinder machine. One or both sides of the board consists of bleached raw material and center plies are generally of less expensive grade.

Patent-Lip Vial: A tooled-neck vial with a square, rather heavy lip. See serum vial.

Pattern Carbon:  Special carbon paper used in business forms that only transfers in certain areas.

Pattern Plate:  The engraving or combination of plates used for making the matrices from which rubber plates are made.

PDF (Portable Document File): Adobe’s PDF is a universal electronic file format, modeled after the PostScript language. It is device–and resolution–independent. Documents in the PDF format can be viewed, navigated, and printed from any computer to almost any printer regardless of the fonts or software programs used to create the original. Printing industry workflows are now primarily PDF-based.

Peelable Lid: Type of flexible lid, generally sealed on top of a tray, and which seal strength is weak enough so as to allow it to be easily peelable through delamination.

Peeling: An open blister.

Peel Seal Coating: Similar to heat-seal coating except that the bond will allow the two materials to be peeled apart.

Pellets: Tablets or granules of uniform size, consisting of resins or mixtures of resins with compounding additives which have been prepared for molding operations by extrusion and chopping into short segments.

Penetration:  The ability of a liquid (ink, varnish, or solvent) to be absorbed into a substrate.

Perfect Bind:  A type of binding that glues the edge of sheets to a cover; like a telephone book, software manuals, or magazines.

Perfecting Press: A printing press that prints both sides of the paper in one pass through the press.

Perforated Tapes:  Paper tape that is perforated when used on a computer typesetter.  The perforated tape can be used to expose and record the wanted type copy for future recall, just like a floppy disc.

Perforation: The practice of creating a long series of holes so that plastic film or paper can be torn more easily. Postage stamps are one common application of this.

Perforations: Consecutive slot/space combination of die-cutting lines.

Performance: The level of effectiveness of carrying out an action or execution of a sequence of events according to a prescribed functional description.

PET – Polyester, (Polyethylene Terephtalate): Tough, temperature resistant polymer. Biaxially oriented PET film is used in laminates for packaging, where it provides strength, stiffness and temperature resistance. It is usually combined with other films for heat sealability and improved barrier properties. A number of our 3M Tapes offer this.

pH:  A number used for expressing the acidity or alkalinity of solutions.  A value of 7 is neutral in a scale ranging from 0 to 14.  Solutions with values below 7 are acid, above 7 are alkaline.

Phenolic:  Generic name for phenol-formaldehyde plastic.

Photo CD:  A proprietary format developed by Eastman Kodak for storing photographic images on a compact disc.  Images can be easily accesses for use in professional printing.

Photocell: A device that is used to activate machines as the package passes a certain reference point.

Photo Composition:  Process of setting type copy photographically, as opposed to using the method of inking and proofing lead type characters.

Photoconductor: In digital imaging, special materials used in electrophotography that are light sensitive when charged by a corona. They then convert light energy (photons) into electrical energy (electrons).

Photo Copy:  A mechanical printing process that uses a light sensitive printing element, magnetic toner and a heating element to fuse the toner to the paper.

Photodegradation: Degradation of plastics due to the action of light.

Photoengraving:  A metal plate prepared by the photochemical process, from which the matrix or rubber mold is reproduced.

Photograph:  An image or picture made by exposing light sensitive film with a camera.

Photo illustration:  An image, primarily consisting of a photograph or composite image containing a photograph.

Photomechanical:  Pertaining to any platemaking process using photographic negatives or positives exposed onto plates or cylinders covered with photosensitive coatings.

Photo plate:  A light-sensitive printing plate.  The plate is developed like film, and then used on a printing press.

Photopolymer Coating:  In photomechanics, a plate coating consisting of compounds that polymerize on exposure. When baked in an oven after processing, this produces tough, abrasion-resistant plates capable of long runs.

Photostat:  A photographic reproduction on paper.  Photostats may be positive or negative.

Phototypesetting:  The method of setting type photographically.

Pica:  Printers unit of measure in typesetting.  One pica = 1/6 inch.

Picking:  Printer’s nightmare that occurs as the surface of a sheet lifts off during printing.  Generally a paper manufacturer’s quality control problem. Alt:  The lifting of the paper surface during printing.  It occurs when pulling force (tack) of ink is greater than surface strength of paper.  Transfers from the substrate web to a roller – gravure.

Piezo: A case printer that can be used to directly print onto corrugated material.

Pigment: The fine solid particles used to give inks color, transparency, or opacity.

Piling:  In printing, the building up or caking of ink on the rollers, plate or blanket; will not transfer readily.  Also, the accumulation of paper dust or coating on the blanket of offset press.

Pillow Pouch: (Three Side Weld) – A pouch made from two pieces of film, sealed on three sides leaving one side open. This has no gusset.

Pinched Neck: A neck defect. A neck which has been pushed or pinched in.

Pinhole: A very small hole in a glass or plastic container, film, etc.

Pin Perforators: A device used to produce small holes in film to allow air to escape during the shrinking process.

Pinpoint Gate: A restricted gate of 0.030 in or less in diameter, this gate is common on hot-runner molds.

Pin Register:  The use of accurately positioned holes and special pins on copy, film plates and presses to insure proper register or fit of colors. Alt: A standard used to fit film to film and film to plates and plates to press to assure the proper registrations of printer colors.

Pit: An imperfection, a small crater in the surface of the plastic.

Pitch Diameter:  The measurement of a gear or plate cylinder, determined by dividing the pitch line (or circumference) by Pi.

Pitch line:  An imaginary circle on the gear, roughly at the point of mesh with the mating gear.  Determines the “repeat” of the gear.  Also equal to the printing repeat of the cylinder.

PIV:  Pulsating Invariable Variator.  A speed variator control is applicable to various types of equipment, with various specific functions.  On a printing press it synchronizes line speed of the press (gear speed) or draw.  

Pixel: Short for “picture element.” A pixel is the small resolvable point of a raster image. It is the basic unit of scanning and digital imaging.

Pixel Depth:  The amount of data used to describe each colored dot on the computer screen, i.e. Monochrome is 1 bit deep, Greyscale is 8 bits deep, RGB is 24 bits deep.  Images to be printed as CMYK separation should be 32 bits deep.

Planned Maintenance: When a company has a given period or periods of production idle times each month in which maintenance activities can be undertaken.

Plastic: A material that contains, as an essential ingredient, one or more organic polymeric substances of large molecular weight. These are solid in their finished state, and, at some stage in their manufacture or processing into finished articles, can be shaped by flow.

Plastic Deformation: A change in dimensions of an object under load that is not recovered when the load is removed.

Plasticity: The ability of a material to withstand continuous and permanent deformation without rupture, when stresses exceeding the yield value are applied.

Plasticize: To render a material softer, more flexible and/or more moldable by the addition of a plasticizer.

Plasticizers:  Liquid or solid additives used to impart flexibility to a dry ink film or overprint varnish.

Plastisol:  A suspension of particles in an organic liquid, similar to an organosol, but containing no solvents.

Plate: (1) Short name for tinplate, black plate, terne plate, aluminum plate or any other basic rolled metal sheet. (2) Verb – To cover or coat with metal, as to plate steel sheet with zinc, tin, etc. (3) A flat piece of metal, rubber or other material, etched, engraved, embossed or other­wise processed with a design to be used as a transfer medium. The plate may also be curved or cylindrical for use on a printing press, a printing plate.

Plate Cylinder:  The cylinder of a press on which the plate is mounted.

Plate Gap:  Gripper space.  The area where the grippers hold the sheet as it passes through the press.

Platen: The flat mounting plates of a press to which the entire printing assembly is fastened.

Plate-Out: An objectionable coating gradually formed on metal surfaces of molds during processing of plastics due to extraction and deposition of some ingredient such as pigment, lubricant, stabilizer or plasticizer.

Plate Ready Film:  Final photographic film used to “burn” printing plates.

Platesetter: An image recorder that images directly on plate material. Platesetters currently available use laser to expose or image paper, polyester, or aluminum plates.

Plotter: 1) A device driven by a CAD system to produce an image on a film, paper or paperboard substrate. 2) A plotter/samplemaker: A device which, in addition to the functions noted above, can produce prototype cut and scored, flat paperboard samples.

Plug: (1) A type of closure designed to be inserted into the opening of a container. May be held by friction or by screw threads. (2) A threaded closure part for metal drums. Usually marketed with a receiving flange which is fas­tened to the drum body or head by welding or other method. (3) A bung. (4) The removable top furnished with certain types of cans.

Plug-and-pack: A multi-vendor drive-controller interface for packaging machinery that is based upon the Open, Modular Architecture Control (OMAC) standard.

Ply: One of the layers of boxboard formed on a multi-cylinder paperboard making machine. Each cylinder adds one web or ply to others which are pressed together and dried to achieve the desired thickness.

Ply Bond: Good ply bond depends on the forming of a strong and elastic network inside the baseboard. This is influenced by the fiber characteristics and consistent sheet formation on the paperboard machine.

PMS (Pantone Matching System): Color charts that have more than 700 pre-printed color patches of blended inks; used to identify, display, or define special “branded” colors.

PMT (Photomultiplier Tube): A light-sensitive sensor that can react to very low light levels by amplifying the signals applied to the sensor during the process. PMTs give drum scanners their superior color separation capabilities.

Pock Marks: Irregular indentations on the surface of a blown container caused by insufficient contact of the blown parison with the mold surface. They are due to low blow pressure, air gas entrapment, or moisture condensation on the mold surface.

Point (paperboard): A term used to designate the thickness of paperboard. One Point equals one thousandth of an inch, or one mil.

Point (printing): Printer’s unit of measurement, used principally for specifying type sizes and leading. There are 12 points to a pica and approximately 72 points to an inch.

Poisson’s Ratio: Measurement of the changes in dimension which occur when a material is stretched. It is obtained by dividing the change in width per unit length by the change in length per unit length.

Polar Solvents:  Solvents with oxygen in their molecule, such as water, alcohols, esters and ketones.

Polyacrylonitrile: (Abbreviation is PAN) a synthetic, semicrystalline organic polymer resin, with the linear formula (C3H3N)n. Though it is thermoplastic, it does not melt under normal conditions. It degrades before melting. It melts above 300 °C if the heating rates are 50 degrees per minute or above. Almost all polyacrylonitrile resins are copolymers made from mixtures of monomers with acrylonitrile as the main component. It is a versatile polymer used to produce large variety of products including ultra-filtration membranes, hollow fibers for reverse osmosis, fibers for textiles, oxidized PAN fibers. PAN fibers are the chemical precursor of high-quality carbon fiber. PAN is first thermally oxidized in air at 230 degrees to form an oxidized PAN fiber and then carbonized above 1000 degrees in inert atmosphere to make carbon fibers found in plenty of both high-tech and common daily applications such as civil and military aircraft primary and secondary structures, missiles, solid propellant rocket motors, pressure vessels, fishing rods, tennis rackets, badminton rackets & high-tech bicycles. It is a component repeat unit in several important copolymers, such as styrene-acrylonitrile (SAN) and acrylonitrile butadiene styrene (ABS) plastic.

Polyamide: (Abbreviation is PA) a macromolecule with repeating units linked by amide bonds. They can occur both naturally and artificially. Examples of naturally occurring polyamides are proteins, such as wool and silk. Polyamides are created artificially through step-growth polymerization or solid-phase synthesis. Examples of synthetic polyamides are nylons, aramids, and sodium poly(aspartate). Due to their extreme durability and strength, synthetic polyamides are commonly used in textiles, automotives, carpet and sportswear.

Polybutylene: (Abbreviation is PB) a polyolefin or saturated polymer with the chemical formula (C4H8)n. It should not be confused with polybutene, a low molecular weight oligomer. Several polybutylene grades are commercially available for various applications and conversion technologies (blown film, cast film, extrusion coating). Polybutylene is used as blend component, predominantly in polyethylene, to tailor peel strength and peel quality in peelable easy-to-open consumer packaging and medical packaging. By blending Polybutylene into polypropylene, heat sealing temperatures as low as 65 °C can be achieved, maintaining a broad sealing window and good optical film properties.

Polyethylene: A simple thermoplastic polymer of ethylene. Highly puncture and tear resistant. Not affected by extreme temperatures. Does not possess barrier properties. Good clarity. It may be low density (see LDPE). medium density (see MDPE). or high density, (see HDPE).

Polyethylene Terephthalate: (Abbreviation is PET) a thermoplastic polymer resin of the polyester family. Used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination with glass fiber. It may also be referred to by the brand name Dacron; in Britain, Terylene or, in Russia as Lavsan.

Polyethylene Terephthalate Glycol: (Abbreviation is PETG) Polyethylene Terephthalate Glycol (PETG) is a water clear material, designed to be very easy to use in a range of applications. It’s a thermoplastic polymer created through the copolymerisation of PET and ethylene glycol.

Polylactic Acid or Polylactic acid: (Abbreviation is PLS) Poly or polylactide is a biodegradable thermoplastic aliphatic polyester derived from renewable resources, such as corn starch, tapioca roots, chips or starch, or sugarcane.

Polymer:  High-molecular-weight organic compound, natural or synthetic, whose structure can be represented by a repeated small unit, the mer: e.g. polyethylene, rubber, cellulose. If two or more monomers are involved, a copolymer is obtained.

Polymerization: A chemical reaction in which the molecules of a monomer (simple chemical) are linked together to form large molecules whose weight is a multiple of that original substance.

Polymerization: A chemical reaction in which the molecules of a monomer are linked together to form large molecules whose weight is a multiple of that of the original substance.

Polyolefin: A generic term used to describe ethylene and/or propylene based plastics. Polyolefin Shrink Wrap / Polyolefin Shrink Film

Polypropylene: A thermoplastic polymer of propylene. Has much higher melting point, thus better temperature resistance than PE. Preserves freshness with vapor and moisture barriers. Non-porous and excellent clarity. Possesses ability to withstand high temperatures. Two types of these film are used for packaging – cast and oriented

Polystyrene: (Abbreviation is PS): Polystyrene is a synthetic aromatic polymer made from the monomer styrene, a liquid petrochemical. Polystyrene can be rigid or foamed. General purpose polystyrene is clear, hard and brittle. It is a very inexpensive resin per unit weight.

Polytetrafluoroethylene: (Abbreviation is PTFE) a fluorocarbon solid, as it is a high-molecular-weight compound consisting wholly of carbon and fluorine. It is more commonly known by its commercial name, Teflon, which was developed by the DuPont company. PTFE is hydrophobic; neither water nor water-containing substances wet PTFE, as fluorocarbons demonstrate mitigated London dispersion forces due to the high electronegativity of fluorine. PTFE has one of the lowest coefficients of friction against any solid.

Polyurethane: (abbreviation is PUR) Polyurethane is a polymer composed of a chain of organic units joined by carbamate links. While most polyurethanes are thermosetting polymers that do not melt when heated, thermoplastic polyurethanes are also available.

Poor Trapping: The press condition in wet printing on letterpress and lithography when less ink transfers to previously printed ink than to unprinted paper. Also called undertrapping.

Porosity: The property of paper that allows the permeation of air, an important factor in ink penetration.

Position Proof: Color proof for checking position, layout, and/or color breakout of image elements. Once called a blue linen or salt print.Today, PDFs are used in some cases.

Positive:  In photography, film containing an image in which the dark and light values are the same as the original.  The reverse of negative.

PostScript:  The computer language most recognized by printing devices.

Pouches/Sachets: A flexible material (usually paper, foil, PE, PET or a multi-laminate) used to package medication.

Pour-Out Finish: A container finish with an undercut immediately below the top, designed to facilitate pouring without dripping. The pour-out finish is used principally for prescription and other drug and chemical containers.

Powered Conveyor: A conveyor equipped with rollers that it powered by an electric motor to transport packages.

Predicted Maintenance: Utilized an array of sensors and/or monitoring equipment to determine the status and condition of critical wear components in machinery and systems to that proactive procedures or replacement can be undertake at a convenient time period before the failure of the component could cause and unscheduled downtime.

Preferential Shrink: The characteristics of a film to shrink more or less in a specific direction.

Preflighting: In prepress, the evaluation and analysis of every component in a file needed to produce a printing job. Preflight confirms the data being submitted, color gamut, color breaks, and any art required (illustrations, transparencies, photos, etc.), plus layout files, fonts, image files, proofs, page sizes, print driver, cropmarks, etc.

Preform: Used in the blow molding processes. A heat-softened polymer is formed into a shape similar to a thick test tube with neck threads. This tube is subsequently inflated while inside a blow mold to create the shape of the desired article.

Prepress: Collective activities of preparing copy for printing. In an analog workflow, it includes color separation, production of films, analog proofs, using the film to make printing plates, and the make-ready of the press. In a digital workflow, this would include manipulating digital files for producing the printing plates, digital proofing, and make-ready of the press.

Pre-Sensitized Plate:  In photomechanics, a metal or paper plate that has been precoated with a light-sensitive coating.

Pre-Separated Art:  Artwork in which the basic layout, register marks and major color is prepared on illustration board and each additional color plate is drawn on a separate sheet or film overlay.

Press and Blow Process: A method of glass container manufacturing of large diameter finish containers in which the parison is shaped by pressing the glass against a blank mold with a metal plunger.

Press Number:  A method of numbering manufacturing business forms or ticks.

Press Proofs: In color reproduction, a proof of a color subject made on a printing press, in advance of the production run.

Pressure Check: An edge or side defect. A check characterized by thin, vertical cracks appearing at the seams.

Pressure Pads: Reinforcements of hardened steel distributed around the dead areas in the faces of a mold to help absorb the final pressure of closing without collapsing.

Pressure-Sensitive Paper:  Paper material with self-sticking adhesive covered by a backing sheet.

Primary Colors:  In paint pigments, pure Yellow, pure Red, and pure Blue are the only hues that can’t be created by mixing any other colors together (see RGB). Printer inks and digital primaries are referred to as Yellow, Magenta and Cyan (see CMYK).

Primary Packaging: Refers to packaging that immediately envelopes a product. It provides most of the strength and the moisture, vapor or grease barrier needed to safeguard a product’s purity, potency and integrity from the time it leaves the assembly line until it’s used by the consumer. Examples of primary packaging include blister packs, clamshells and trays.

Prime Coat:  Base coat applied first to enhance subsequent printing.

Print & Apply: Machine that prints the label and then applies it to the package.

Printability (paperboard): Printability is the paperboard’s ability to reproduce images and texts. The measurable paperboard properties that are most related to printability are surface strength and surface tension. In modern multicolor printing, fast print speeds and tacky inks place very high demands on a strong, uniform surface strength. Surface tension involves the adhesion ability of a specific liquid (e.g. ink). The better and more uniform the ink adheres to the surface, the better results you get when printing.

  • Important paperboard features for printability and high print quality are whiteness, smoothness, gloss, ink absorption and drying, flatness and dimensional stability, moisture content, rub resistance, ink and varnish gloss enhancement, and clean, dust-free edges and surfaces.

Print Quality:  A term describing the visual impression of a printed piece.  In paper, the properties of the paper that affect its appearance and the quality of reproduction.

Process: The succession of actions undertaken to make a package.

Process Colors: The subtractive primaries: yellow, magenta, and cyan, plus black in the four-color process printing. Referred to as CMYK.

Process Control:  That procedure for examining a process, which aims at evaluating future performance through the use of statistical quality control methods.

Processing Aids: Additives specifically used to improve the injection process.

Process Inks:  For high reproduction illustrations by halftone color separation process.  Colors are:  yellow, magenta, cyan, with or without black.

Process Lens:  A highly corrected photographic lens with a flat field for graphic arts line, halftone and color photography.

Process Printing: Printing from a series of two or more plates to produce intermediate colors and shades.

Product: Those items used or consumed by the customer.

Production Artist (pasteup artist):  A skilled laborer who produces finished, camera-ready, or plate-ready artwork from the visual elements and instructions provided by the designer or client.

Production Run:  The final printing requested by the customer from the original artwork.

Productivity: The level of ability or effectiveness in marketing, manufacturing, distributing, and servicing a package.

Product Specifications: The written description of the products to be manufactured.

Progressive Proofs (progs):  Proofs made from the separate plates in color process work, showing the sequence of printing and the result after each additional color has been applied.

Proof: A trial impression made in conjunction with a printing process to determine the need for corrections. Impressions must be taken singly from each color plate of a set, showing each color alone and in combination with each of the other colors in proper sequence. Proofs should be made on the substrate to be used and with the inks to be used for actual production.

Proofing: The stage of making a number of trial prints to judge the final result prior to editioning.

Propellant: The gas generating the pressure which serves to discharge the product from an aerosol container.

Proportional Limit: The greatest stress which a material is capable of sustaining without deviation from proportionality of stress and strain. (Hooke’s Law).

Prototype Mold: A simplified mold construction often made from a light metal casting alloy or from an epoxy resin to provide actual molding for evaluation and testing prior to production mold consideration.

Prototype Tool: A preliminary mold upon which the final mold will be based.

Psychrometer:  A wet-and-dry bulb type of hygrometer.  Considered the most accurate of the instruments practical for industrial plant used for determining relative humidity.

Pulled Gate: Area where the part was connected to the sprue or runner that has been drawn out or stretched from the surface.

Pulp: The basic cellulose fibers resulting from the chemical or mechanical separation of fibers from wood, fiber crops or reclaimed paper.

Puncture Resistance: The ability of a material to resist progressive tearing once it has been pierced or cut.

Puncture Test: Determination of the resistance of fiberboard to puncturing. Usually achieved by using a pyramidal metal point driven into the specimen by the swinging action of a pendulum.

Purging: In extrusion or injection molding, the cleaning of one color or type of material from the machine by forcing it out with the new color or material to be used in subsequent production, or with another compatible purging material.

Purity: See Virgin fibers

Push Up: The recessed area on the bottom of a container designed to allow a stable bearing surface on the outside edge and prevent rocking.


Quality Control: A system for assuring that commercial products meet certain standards of identity, fill container, and quality sanitation and adequate plant procedures.

Quality Package: A package that meets all design specifications

Quart: The quart is an imperial and US customary unit of volume, equal to one quarter of a gallon

Quick Changeout: The total downtime between production runs of different packages or the end of first production run to end of the next production run time


Ragged Left: In typesetting, type that is justified to the right margin and the line lengths vary on the left.

Ragged Right: In typesetting, type that is justified to the left margin and the line lengths vary on the right.

Ragger: A device which removes rags and similar contaminants from recycled material during the pulping operation. Normally installed on a beater machine.

Railroading:  Printing of a continuous mark or line on the non-image areas of a design, often resulting in the marking or scratching of a cylinder.  Can be caused by particles lodged behind the doctor blade.  

Railroad Tracks:  A streak developed by oscillation of a nicked doctor blade, resulting in a heavy, wide line printed on the web at the ends of the stroke, with fine lines running in between.

Raised Ejector Site: Where the ejector site is either heightened or raised above the surface of the component.

Ram: The forward motion of the screw in the plasticator barrel that forces the melt into the mold cavity.

Ramp: A small depressed cavity (detent) in the base of the bottle to act as a guide in positioning the bottle in the decorating machine for application of Decorating.

Random Repeat: Refers to the randomness of artwork to be printed, most often, on plastic film, but not positioned in the exact same location on every bag or length of tubing. This type of printing is extremely beneficial in saving money, by allowing fewer plates to be used while printing many images. The printing length of a plate cylinder is determined by one revolution of the plate cylinder gear.

Raster Image Processor (RIP): A computer process that converts image areas to an electronic bitmap. An integral part of the computer to press (CtP) or “filmless” printing process.

Reaction Injection Molding (RIM): A process that involves the high pressure impingement mixing of two or more reactive liquid components and injecting into a closed mold at low pressure.

Reagent Resistance: The ability of a plastic to withstand exposure to chemicals.

Ream:  Five hundred sheets of paper.

Recessed Panel: A container design in which the flat area for labeling is indented or recessed.

Reclosable Bags: Seal-top reclosable bags can be made with or without a tamper-evident adhesive seal. Also includes zipper and slider zipper bags

Recovered Fibers: Unlike virgin fibers, recovered or recycled fibers are derived from recycled paper waste. Since recovered fibers are of unknown origin, they may contain impurities.

Recovery: Stretch film will try to return back to its original form after it has been stretched. This action constantly pulls the load together, since the stretch film tightly form-fits the load. Stretch wrapping continues to tighten the load as it settles during shipment due to the recovery property, keeping the load safe and secure during shipment.

Recovery Time: The length of time for the screw to rotate, create a shot, and return to original position.

Recto:  Right-hand page of an open book.

Recyclable: Packaging materials or packages that may be reprocessed into raw materials for subsequent re-conversion into packages or for secondary purposes.

Recycled Material (Fiber): Reclaimed material which, are repulping, is used as one of the two principal furnishes for paper or paperboard. This includes boxboard cuttings, over-issue newspaper, reclaimed corrugated containers, mixed paper, tabulating cards, envelope cuttings, kraft cuttings, etc.

Recycled Paperboard: Manufactured from pre- and post-consumer waste. Pre consumer waste is mill conversion waste, in other words, paper products that haven’t made it to market. Post consumer waste consists of paper products that have been used and discarded. Recycled paperboard is six to nine ply, and has a less desirable printing surface than SBS.

Reducers:  In printing inks: varnishes, solvents, oily or greasy compounds used to reduce the consistency for printing.  In photography: chemicals used to reduce the density of negative or positive images or the size of halftone dots (dot etching) Alt: Copy that is not transparent.

Reflection Copy:  In photography, illustrative copy that is viewed and must be photographed by light reflected from its surface.  Examples are photographs, drawings, etc.

Reflective Process Camera:  A camera that is capable of reproducing an original image that has been prepared on an opaque substrate.

Register:  In printing, fitting of two or more printing images in exact alignment with each other. Alt:  To properly position the print in relation to the edge of the sheet and to other printing on the same sheet.

Register (paperboard): Register is the paperboard’s ability to retain its shape and dimensions throughout all printing and finishing operations. This ability is crucial for achieving excellent precision in multi-step processing. Of course, even in a single operation such as multi-color printing, the flatness and dimensions of the paperboard must remain exactly the same after passing each different printing unit.

Register Marks:  Crosses or other targets applied to original copy prior to photography.  Used for positioning films in register, or for register of two or more colors in process printing.  Alt:  Cross-hair lines or marks on film, plates, and paper that guide strippers, platemakers, pressmen, and bindery personnel in processing a print order from start to finish.

Registration:  The quality of alignment of the different colored inks as they are applied to paper, i.e. If the inks can be seen to overlap improperly or to leave white gaps on the page, the printing is said to be “out of registration” or “poor register”.

Registration Print: The lining up 1 or more colors in printing to achieve the same placement on a substrate each and every time.

Regrind: Waste material such as sprues, runners, excess parison material and reject parts from injection molding, blow molding and extrusion, which has been reclaimed by shredding or granulating. Regrind is usually mixed with virgin compound at a predetermined percentage for re-molding.

Regular Number: The quantity of boxboard sheets, 25″ x 40″ (1,000 square inches) required to make a bundle of 50 pounds.

Regular Slotted Container (RSC): A box style made from a single sheet of corrugated that has been scored and slotted to allow for folding.

Reinforced Plastic: A plastic composition in which fibrous reinforcements are embedded, with strength properties greatly superior to those of the base resin.

Relative Humidity: The ratio of actual humidity to the maximum humidity that air can retain without precipitation at a given temperature and pressure

Release Agent: A material sprayed on the mold which facilitates removing the part.

Release Coating: A coating applied to the non-sealing side of cold-sealable packaging films and laminates supplied in a roll form, that will allow the packer to unwind these films or laminates on packaging machines.

Relieved Area: An area that is pre-designed into a package for easier opening.

Renewable: Material that can be renewed/replaced, such as wood, and for which production is therefore sustainable over the long term.

Repeat: The printing length of a plate cylinder determined by one revolution of the plate cylinder gear..

Repeatability: The ability to keep photographic film (and the images thereon) in proper register in imagesetters, film plotters, and platesetters. Repeatability is usually measured in micrometers.

Repiscreen: In halftone photography, a contact screen with 110-line screen ruling in the highlights and 220-line in the middle tones and shadows to produce a longer scale and smoother gradation of tones in the light areas of the copy.

Reprography: Copying and duplicating.

Resin: Any of a class of solid or semi-solid organic products of natural or synthetic origin, general­ly non-crystalline and of high molecular weight with no definite melting point. Resins are gen­erally water-insoluble and have little or no tendency to crystallize. However, certain resins used in packaging, such as polyvinyl alcohols and polyacrylates, are readily dispersible in water, and others, such as polyamides and polyvinylidene chloride are readily crystallized.

Resist:  In photomechanics, a light-hardened stencil to prevent etching of non-printing areas on plates.

Resolution: Ability of an input device to record, or an output device to reproduce, the fine detail of an image. There is a difference between resolution and addressability, or sampling rate. Resolution concerns how closely spots can be placed, and also whether gray levels can be distinguished. Resolution for output devices depends on addressability, bit-depth, and mark size.

Respi Screen: A contact screen with 110-line screen ruling in the highlights and 220-line in the middle tones and shadows. Produces a longer scale and smoother gradation of tones in the light areas of the copy.

Restricted Gate: A very small orifice between runner and cavity in an injection mold. When the part is ejected, this gate readily breaks free of the runner system. Generally, the part drops through one chute and the runner system through another, leading to a granulator and scrap reclaim system.

Retainer Plate: The plate on which demountable pieces are mounted during molding; Parts  such as mold cavities, ejector pins, guide pins and bushings.

Retarder: Solvents added to ink to slow the evaporation rate.

Retort: The thermal processing or cooking packaged food or other products in a pressurized vessel for purposes of sterilizing the contents to maintain freshness for extended storage times. Retort pouches are manufactured with materials suitable for the higher temperatures of the retort process, generally around 121 degrees C.

Retort Pouch: A flexible pouch, usually made with aluminum foil laminates, filled with a food product and designed to withstand the temperature and pressures of processing in a pressure-balanced retort.

Retractable Cores: Used when molding parts in cavities not perpendicular to the direction in which the part is ejected from the mold. The cores are automatically pulled from the mold prior to the mold opening,reinserted when the mold closes again and prior to injection.

Retrofit:  Backwards integration of advanced capability into a device or program not originally intended for that purpose.

Returnable Package: A container designed for return to the filler of the product it contains, to be refilled with the same product.

Reusable Package: A container which, when emptied, can be used to package either the same or different products.

Reverse Angle Doctor Blade:  In flexography, similar to doctor blade in gravure except used with much lighter pressure and a reverse angle on the anilox roll.

Reverse Plate:  A plate on which the reproduction of an original design is produced in negative form.

Reverse Printing:  Printing on the underside of a transparent film.  Design in which the copy is “dropped out” and the background is printed.

Reverse Tuck End (RTE): Folding carton where end tucks are extensions on opposite panel.

Rewound:  After the desired substrate has been printed,it is taped to a shaft and wound back into the original unprinted roll form.

RGB:  Red, Green, Blue – additive primary colors.

Rhodamine Reds:  A class of clean, blue shade, organic reds possessing good light fastness. Often called magenta in process printing.

Rib: A reinforcing member of a molded part.

Right-Angle Fold:  In binding, a term used for two or more folds that are at 90 degree angles to one another.

Rigid Package: A non-collapsible, non-flexible package that has a fixed shape and retains that form whether full or empty.

Rigid Set-up Box: A stiff paperboard box in three-dimensional construction, generally overwrapped with printed paper, and delivered “set-up” ready to use.

Ring Gate: Used on some cylindrical shapes. This gate encircles the core to permit the melt to first move around the core before filling the cavity.

Rip Film:  A method of making printing negatives from PostScript files created by desktop publishing.

Robot: Automated devices for removing parts upon ejection from an open mold, rather than letting the parts drop. Robots also can perform secondary functions, such as inspection, degating, precise placement of parts on a conveyor, etc.

Rocker: A container with a bulged or deformed bottom, causing the container to rock when in an upright position.

Rocker Bottom: A bottom defect. A bottom which has sagged so that the container is unstable when placed on a flat surface.

Rockwell Hardness Test: A test for determining hardness of steel and tinplate, used as a guide in determin­ing plate temper and suitability for metal packaging applications.

Rods: Glass and polyethylene rods are used particularly in the drug and cosmetic industries. One of the most common is a balled-end rod for touch applying medicines.

Roll: A quantity of material supplied in web form, such as paper, film, or aluminium foil when wound into cylindrical form on a shaft or core.

Roller Conveyor: Conveyor that utilizes rollers and can be powered or not powered

Roller Stripping:  In lithography, a term denoting that the ink does not adhere to the metal ink rollers on a press.

Rollout:  Ink spread using a hand-roller, for testing or sampling purposes.

Rotary Die: The die used in the rotary diecutting process.

Rotary Diecutting: Cutting and creasing by means of arcuate metal dies mounted on a backup cylinder so as to permit continuous cutting and scoring of a paperboard sheet.

Rotogravure: An intaglio printing process using cylinders on which an image is etched in the form of a series of cells. These cells are filled with ink and the excess removed by a doctor blade. Ink from the wells is transferred by the rotary action of the press to the board in either sheet or web form.

Roto News:  Any of five grades of uncoated groundwood, manufactured expressly for gravure printing.

Rough Finish: A finish defect. A finish which has irregular, minute imperfections causing a rough surface.

Rust Inhibitor: A chemical agent contained in a coating material which is applied to metal surfaces to prevent or reduce rusting. See also: Corrosion.

RRP: Retail Ready Packaging

RSC: Regular slotted cardboard

Rub and Scratch Resistance: It is essential for the printed ink or varnish film to be durable during normal handling. Rub and scratch resistance depend greatly on having a smooth paperboard that has good absorption and drying properties. The interrelationships between the paperboard surface, the printing and varnishing processes, and the ink and varnish formulation are crucial for achieving good rub and scratch resistance.

Rubber:  An elastomer material that is capable of recovering from large deformations quickly and forcibly.

Rub-Proof: An ink that has reached maximum dryness and does not mar with normal abrasion.

Rub Test:  See abrasion test.

Rubylith:  A hand cut masking film used in screen and flexographic printing.

Run-Around:  In composition, the term describing type set to fit around a picture or other element of the design.

Runnability:  Paper properties that affect the ability of the paper to run on the press. Alt: The physical ability of a roll of paper or substrate to pass through a press under prevailing conditions of tension and speed without web breaks.  Distinguished from printability.

Runner: In an injection mold, the feed channel, usually of circular cross section, which connects the sprue with the cavity gate. The term is also used for the plastic piece formed in this channel.

Runner Balancing: Developing a runner system which delivers the required amount of melt to each cavity with the correct pressure to fill all the cavities simultaneously at the correct temperature for the part.

Runner Design: Using the runner as a flow control device by positioning the gate and using the size of the runner to control the filling pattern within the cavity, in addition to its purpose of getting the melt into the cavity.

Runnerless Molding (also known as Hot-Runner Mold or Insulated Runner): A mold in which the heated runners are insulated from the chilled cavities. Hot-runner molds make parts that have no scrap.

Runner System: This term is sometimes used for the entire resin feeding system, including sprues, runners and gates, in injection molding.

Running Head:  A headline or title repeated at the top of each page.

Running In:  The process of seating a doctor blade to a cylinder.  Also called toning in.

Running Register:  The control on a flexographic press which accurately positions the printing of each color station in the direction of the web travel.  Also called Circumferential register and Longitudinal register.

Run speed: The instantaneous operating rate at some point in time.

Run Utilization: The fraction of time the packaging line is producing output at a set run speed divided by the total time available for production.


Safety-Closure: A closing device which cannot be opened unless specific directions are followed. Used on hazardous materials and on drugs, e.g. child-proof closure.

Sample: Basic optical image element (analog) taken by the image sensor of a camera or scanner. A sample may be black and white, or it can be for several color channels. The sample is processed to obtain a pixel. Processing may involve conversion from device RGB to some standardized color space.

Scale:  A defect in coated papers consisting of slightly colored reflective spots, caused by dry coating material embedded in the paper during calendering.

Scaling: Determining the proper size of an image to be reduced or enlarged to fit a designated area.

Scanner:  An electronic device used to make color separations, halftones, duotones and tritones.  Also a device used to scan art, pictures or drawings in desktop publishing.

Score:  A disruption, such as a notch, groove, cut or partial depth cut, in the surface of a substrate such as paperboard.

Scoring: To impress or indent a mark in the printed paper to make folding easier and reduce the likelihood of cracking the paper.

Scrap: Any output of a mold that is not usable as the primary product.

Scrap Material: A product made non-usable for its original purpose during the manufacturing process, or spoilage depreciation, which may be reclaimed as a raw material or as a component of another material or product. The trim areas between cartons on a sheet.

Scratch Resistance: See Rub and scratch resistance

Screen: Woven metal screens installed across the flow of plastic in a plastic extruder. Supported by a breaker plate, the screens strain out contaminants and increase back pressure.

Screen Angles:  In color reproduction, angles at which the halftone screens are placed in relation to one another, to avoid undesirable moiré patterns.  A set of angles often used is:  black 45E, magenta 75E, yellow 90E, cyan 105E. Alt:  Frequently a desktop publisher’s nightmare.  The angles at which halftone, duotones, tritones, and color separation printing films are placed to make them look right.

Screened Print:  In photography, a print with a halftone screen made from a halftone negative or by diffusion transfer.

Screening: That part of a RIP (Raster Image Processor) that calculates the tonal values of each spot for an output device. The function of a screener is device dependent because it is related to the resolution of the output devices.

Screen-Printing:  In flexography, refers to any tone printing work, whether halftone or Ben-Day.

Screen Ruling: Screen ruling is a measure of the information density of a picture. It is measured in dpi or ppi (dots per inch or pixels per inch), with a higher number indicating higher resolution. High screen ruling means printing with high resolution, which requires a very smooth substrate with very uniform surface characteristics.

Screen Sizes:  Designated by the number of halftone dots in one linear inch of perpendicular or horizontal ruling.

Screw: The plastic extrusion feed screw, which can be a single or twin screw, is part of the plastic extrusion machine. It sits in the barrel of the machine, forcing the plastic material along the barrel.

Screw Cap: A cylindrical closure having a thread on the internal surface designed to engage a compatible external thread on the finish or neck of a container.

Screw-Thread Vial: A vial with a very short neck and an outside screw-thread finish.

Screw Travel: The distance the screw travels forward when filling the mold cavity.

Scribe Lines:  The fine lines on the surface of the plate cylinder that aid in mounting rubber plates accurately.  Center lines or other positioning guide lines applied to the non-printing areas of a rubber printing plate, to facilitate mounting on a cylinder.

Script:  A typeface that mimics the appearance of handwritten text.

Scuff:  The action of rubbing again with applied pressure.  The damage that has taken place through a rubbing.

Scum: In offset lithography, a film of ink that prints in the non-image areas of a plate where it should not.

Scumming: A deposit on ink on the non-printing areas of a gravure cylinder often leaving a residual haze over a large area of web.

S Dimension: Locates the position of the bottle thread with respect to the sealing surface. The “S” dimension is the vertical distance from the sealing surface to the intersection of the finish wall and the top part of the first part of bottle thread where full depth contour exists.

Seal-end Carton: A carton, which is glued along the depth dimension by the manufacturer. Its top and bottom flaps are folded over the open end and glued after it is filled with the product.

Sealing Solvent:  Small amounts of a volatile organic liquid are used to soften the coating or surface of the material to the point where the materials will adhere when the solvent evaporates.

Sealing Surface: The lip portion of the finish that makes contact with the sealing gasket or liner to form a seal.

Seal Strength: Measurement of force required to break or destroy a heat seal formed by any of the heat sealing sheets.

Seal Wire: An element made from nichrome wire used to seal film.

Seam: The junction created by any free edge of a container flap or panel where it abuts or rests on another portion of the container and to which it may be fastened by tape, stitches or adhesive in the process of closing the container.

Seamless: Without a seam or joint as applied to a plastic container or to a one-piece metal can body produced by the drawing process. A two-piece can.

Seam on Top/Side of Finish: A finish defect. A fin of glass across the top or the side of the finish.

Secondary Colors:  Those obtained by mixing any two of the primary colors in equal proportions.

Secondary Packaging: The outer package into which the primary package is placed. Its major function is to protect the product during shipping and distribution. Examples of secondary packaging include cartons, containers and pallets.

Security Wrap: Opaque pallet stretch film. Opaque film blocks UV rays from damaging products. Protects shipments during transit by not allowing contents to be seen.

Selvage: Another term for trim waste.

Semi-Automatic: Machinery that has automatic applications, but still requires assistance from an operator

Semi-Bending Chipboard: Chipboard which when properly creased will take a 90° bend without showing pronounced failure in the top liner fibers.

Separations:  A set of three or four continuous tone or halftone negatives made by color filter exposures from a full color film transparency, photographic print or painting.  Each negative represents one of the printer colors abstracted.  They are used to make printing plates in color process printing.

Serif:  The curls and points that appear as adornments on some typefaces.

Serum Vial: A vial having a neck with a relatively small opening to receive a rubber plug stopper and aluminum seal.

Service Bureau:  The facility that provides professional services to graphics and printing professionals.  (i.e. plate ready film, match prints, color keys, etc.)

Set:  The strain remaining after complete release of a load producing the deformation in rubber.

Set-Off:  In presswork, when the ink of a printed sheet rubs off or marks the next sheet as it is being delivered.  Also called offset.

Set Up: The process of getting a printing press ready to print a job. Also referred to as “Change Over”, when a finished job is complete and the new job is being transferred onto the press.

Set-Up Box: A stiff paperboard box in three dimensional construction, typically fabricated from grades of non-bending chipboard, which is over-wrapped with printed paper or covering materials and delivered “set-up” and ready to use; as distinguished from a folding carton.

Shade:  A color produced by a pigment or dye having some black mixed in, darkening it.  Opposite of tint.

Shading:  The addition of a color, shade or tone to suggest three-dimensionality, shadow or diminished light in a picture or design.

Shadow: The darkest parts in a photograph, represented in a halftone by the largest dots.

Shape: In the Glass and Plastic product types, Shape refers to the shape of the bottom of the container.

Sharpen: To decrease in color strength, as when halftone dots become smaller; opposite of dot spread or dot gain.

Sharp Wipe:  The resultant angle of the doctor blade to the cylinder as the doctor blade angle is decreased.  Also referred to as Steep Wipe.

Shear Marks: A general defect. C-shaped marks making a definite line in the glass.

Shear Rate: The rate at which a layer of melt slides over the layer below. Shear rate is velocity-related rather than force-related.

Shear Strength: The maximum load required to shear the specimen in such a manner that the moving portion has completely cleared the stationary portion.

Shear Stress: The shearing force divided by the area. It is always highest at the outside of the flow channel. As it is force-related, it depends on the viscosity of the material, which in turn depends on the material and molding conditions. The maximum allowable stress level is usually taken as 1% of the tensile strength of the material. High shear stress is unimportant at gates, and in sprues and runners.

Sheet: A rectangle of combined board, untrimmed or trimmed, and sometimes scored across the corrugations when that operation is done on the corrugator. Also, a rectangle of any of the component layers of containerboard, or of paper or a web of paperboard as it is being unwound from the roll.

Sheet Feeder: A plant that operates a corrugator, but does not posses converting equipment. Sheet feeder plants produce corrugated sheets exclusively for box plants to convert into boxes.

Sheeting: Sheets are distinguished from films in the plastics industry only according to the thickness. Plastic sheeting is most commonly made by sheet extrusion and casting in the plastics industry. Post extrusion processes for plastic sheet is thermoforming and vacuum forming.

Sheet Plant: Does not have a corrugator but does have converting equipment. Sheet plants purchase corrugated sheets from a corrugator plant or sheet feeder.

Sheetwise: To print one side of a sheet of paper with one plate, then turn the sheet over and print the other side with another plate using same gripper and opposite side guide.

Shelf Life: The length of time that a product will maintain market acceptability under specific conditions of storage.

Shelfline: A line of glass containers (used by drug and chemical companies) that was designed to give the packer specific advantages on label space, maximum size, appearance and easy pouring, combining the best features of Boston Round and F-style containers.

Shelf Ready Packaging: Name given to transit packaging that can be used to display the products on a shelf without removing the product.

Shell: (1) A cylindrical seamless part drawn from flat sheet metal. (2) A plain, unprinted carton designed to be overwrapped with paper. (3) Any rectangular tube open at both ends for a set-up paper box. (4) A collapsible tube de­signed for one single application of contents. Has no neck, orifice or cap, but has a shoulder which forms the closed end of the container. Designed to be opened by puncturing, tearing, breaking off a small tip, etc. Shells are also called “‘one shot” or single dose or blind neck tubes. (5) The body sidewall of a drum. (6) The outer sec­tion of a fiber drum sidewall. (7) A sheet of cor­rugated or solid fiberboard scored and folded to form a joined or unjoined tube open at both ends. Used as inner packing. (8) The flat topped, threaded part of the screw cap which pulls the liner down to seal the finish of the con­tainer.

Shellac:  An alcohol-soluble, natural resin widely used in flexographic inks.

Shell Cup:  A device for measuring viscosity.

Shell Vial: A cylindrical container, usually made of glass, characterized by having straight sides, being neckless, and having a flat bottom. Made by sealing one end of a glass tube of appropriate diameter and length.

Shingling: In image assembly and layouts, the center (or gutter) margin is varied according to the position of the page in the signature and the bulk of the paper.

Shipping Container: A corrugated or solid fiber box used to pack and transport products or packages. Also referred to as a shipper.

Shock Test: The application of sudden forces to a filled container to determine its performance under conditions simulating those that may encountered during shipment. Also known as a drop test. See also: Vibration test

Shore Hardness: A method of determining the hardness of a plastic material using a scleroscope or durometer. The Shore Scleroscope measures hardness in terms of the elasticity of the material. The device consists of a small conical hammer fitted with a diamond point which falls inside a glass tube. The hammer is made to strike the material under test and the degree of rebound is noted on a graduated scale. Generally, the harder the material, the greater will be the rebound.

Short Ink: An ink that is buttery and does not flow freely.

Short Shot (also known as Non-Fill): Failure to completely fill the mold or cavities of the mold. Edges may appear melted.

Shot: One complete cycle of a molding machine.

Shot Capacity: Generally based on polystyrene, this is the maximum weight of plastic that can be displaced or injected by a single injection stroke. Generally expressed as ounces of polystyrene.

Shoulder: (1) That part of a container between the main body and the neck. (2) That portion of a closure immediately adjacent to and including the corner where top and skirt join. (3) In a can, an off-set on a straight side to act as a stop or support.

Shoulder Box: Lid of box does not overlap the base, the box has a 2nd, shorter liner or tray wrapped and glued inside the base, creating a lip and support for the lid to rest on the base tray.

Shoulder Check: A shoulder defect. A check which is shallow and in the surface, usually wavy in appearance.

Show-Through: The undesirable condition in which the printing on the reverse side of a sheet can be seen through the sheet under normal lighting conditions.

Shrink: Defined as the ability to become smaller.

Shrinkage: Contraction upon cooling of the part. Shrinkage occurs less is disorientated material and more across chains of molecules than along their lengths. Lower pack area have lower areas of orientation and shrinkage

Shrinkage Allowance: The dimensional allowance which must be made in molds to compensate for shrinkage of the plastic compound on cooling.

Shrink Tunnel: A type of equipment featuring a chamber producing heat and airflow designed to shrink film.

Shrink Wrapping: A technique of packaging in which the strains in a plastic film are released by raising the temperature of the film, thus causing it to shrink over the package.

Side-Draw Pins: Projections used to core a hole in a direction other than the line of closing of a mol. Must be withdrawn before the part is ejected from the mold.

Side Drive: A machine that drives a package using motorized side belts.

Side Guide: On sheetfed presses, a guide on the feed board to position the sheet sideways as it feeds into the front guides before entering the impression cylinder.

Side-Gusset Pouch: A Pouch with gussets on both sides, with a fin-seal running from top to bottom, sealed horizontally at the bottom and the top. Commonly used in the coffee industry.

Side Register: The control of print register on the horizontal axis, i.e., from one edge of the web to the other.

Side Seam: (1) A seam joining the two edges of a blank to form a container or can body. In a three-piece can, made by soldering, welding, gluing, or bonding. Main types of construction are lock seam, lap seam, Mennen seam. (2) A seam formed on one side of a paper or plastic bag rather than at its center.

Side Weld:  In bag making, refers to the seal formed by a hot knife cutting through two layers of thermoplastic material, like polyethylene, and sealing that edge.

Side Wire:  In binding, to wire the sheets or signatures of a magazine or booklet on the side near the backbone.

Sift Proof: A carton constructed in such a way as to prevent granular or powdered contents from escaping.

Silhouette Halftone: A halftone of a subject with all of the background removed.

Silicating: A surface treatment using silicate to lay the fibers and produce a smooth finish on board and minimize dusting.

Single Face: In the manufacture of corrugated board, one piece of fluting glued to one liner only.

Single Wall: The conventional method of making corrugated board. A fluting medium is sandwiched between two liners (liner-fluting-liner).

Singlewound Film (SW): A single layer of shrink film wrapped around a core.

Sink Mark: An indentation on the surface of the part as a result of significant local change in wall section. The mark will occur in the thicker area.

Sizing: Material added to the furnish for paper or board, or the application of material to paper or board which increases the resistance of the sheet to penetration by liquids.

Skid:  A pallet used for a pile of cut sheets.

Skin: A relatively dense layer at the surface of the material.

Skin Packaging: See Contour Packaging.

Skirt:  The portion of a bag between the bottom seal and the bottom edge of the bag.

Sleeve: (1) A tubular form made of various mate­rials, usually open at both ends, made in various shapes, which is slipped over or in an item. (2) A tubular carton with open ends.

Slide: Projection in the mold used to form the geometry of the part. It is not in the direction of the closing of the mold and must be withdrawn before the part can be ejected.

Slime Hole:  A paper defect caused by bacteria or fungus replacing or imposing themselves upon paper fibers.

Slip: The quality of a film to move over surfaces with little resistance. Additive that helps prevent bags from sticking to each other and promotes easy insertion of packaged goods.

Slip Compound:  An additive for ink that imparts lubricating qualities to the dried ink film.

Slipped Core:  A paper defect in which the paper in a roll is not properly glued to the core.

Slip Sheet: A flat sheet of material used as a base upon which goods and materials may be assembled, stored and transported.

Slit: A cut made in a fiberboard sheet without removal of material.

Slit Score: A cut made in fiberboard extending through only a portion of the board, creating a fold.

Slitter:  A machine to cut roll stock in the long direction. Three types are widely used: Razor blade slitter, Sheer slitter, or Score cutter.

Slitter Turnover:  An edge break on a roll of paper caused by a slitter, which turns over during winding.  The edge of the break protrudes from the roll.

Slot: A wide cut, or pair of closely spaced parallel cuts including removal of a narrow strip of material made in a fiberboard sheet, usually to form flaps and permit folding without bulges caused by the thickness of the material.

Slug:  A rubber plate section, usually type, used as an insert.

Slug Hole:  A paper defect resulting from the paper machine picking out a group of fibers superimposed over the sheet.

Slur:  A condition caused by slippage at the moment of impression between any two of the following: substrate, plate, blanket.

Slurry:  A suspension of solids in water.

Slur Stick:  A small, specially designed stick of wood or other soft material used to dislodge foreign particles from the edge of a doctor blade.

Small Flute Paperboard: A term preferred by the folding carton industry to identify small height corrugated grades (E, F, G, and N flute) which can be converted on folding carton equipment, as opposed to larger flute grades (A, B, and C) used primarily for shipping containers. May also be referred to as “Mini-Flute” or “Small Flute” corrugated.

Smoothness:  A physical characteristic of paper, describing its levelness or flatness, essential for total contact with the gravure cylinder.

Snap:  The action of the mesh continually lifting away from the paper during printing.

Snowflaking:  Condition of a printed area characterized by very small dots of unprinted areas showing throughout a deposited ink.

Soft Dot: Halftone dot with considerable fringe that causes dot gain or sharpening in printing or photography.

Soft End:  A paper defect caused by web thickness variation – one part of the roll feels soft compared with an adjacent end.

Softening Point:  Temperature at which plastic material will start to deform with no externally applied load.

Soft Ink:  Descriptive of the consistency of paste inks.

Soft Temper Foil: Foil completely softened by thermal annealing treatment.

Soldering: Method for sealing the side seam and other joints of metal cans using a tin-lead alloy. Soldered seams are usually folded or hooked (lock seam), and must be lacquered to prevent corrosion and migration of metals into the product.

Solid Bleached Sulfate (SBS): This high quality board is used when premium imaging is important. All layers of the board are uniformly white from the bleaching process. Made from 100% virgin pulp, SBS is known for its consistent properties and overall strength.

Solid Loading:  The spring, hydraulic, or pneumatic cylinder in a press.  When completely compressed, it results in direct loading.

Solids Content:  The percentage of solid material contained in an ink formulation; includes pigment, extender, binder, plasticizers and wax.

Solid Unbleached Sulfate (SUS): Also referred to as Coated Unbleached Kraft (CUK), Coated Natural Kraft (CNK), Solid Unbleached Board (SUB), Clay Coated Kraft Back (CCKB) – Recycled paperboard that is brown on one side and clay coated on the other.

Solvent:  Liquid which dissolves a solid. In ink, the evaporation of solvent leaves the solids behind as an ink film on the substrate.

Solvent Coating:  A type of coating, applied in liquid form, which dries by evaporation.

Solvent Load:  The maximum rate of solvents to be evaporated in a dryer or solvent recovery system.

Solvent Release: In ink, the ability of a binder to influence the rate of evaporation of a solvent.

Souring:  The precipitation or coagulation of the ingredients of an ink due to the presence of water or other foreign materials.

SPC:  Acronym for statistical process control.

Specifications:  A precise description of a print order.

Specific Gravity: The ratio of the density of a material as compared to the density of water at standard atmospheric pressure (1 ATM) and room temperature (73F).

Specific Heat: The amount of heat required to raise a specified mass in plastic by one unit of a specified temperature.

Specific Volume: The volume of a unit of weight of a material; the reciprocal of density.

Spectrophotometer:  The most sophisticated instrument for measuring brightness and color, able to test at varying wavelengths.

Spectrum: The complete range of colors in the rainbow, from short wavelengths (blue) to long wavelengths (red).

Specular Gloss Test:  A means of measuring paper or ink gloss by determining the amount of light reflected from a sample at specified angles.

Spike: A bottom defect. A small projection of glass or plastic in the center of the bottom of the container.

Spiral Binding:  A book bound with wires in spiral form inserted through holes punched along the binding side.

Spiral Flow: Test performed by injection molding a sample into a spiral mold; used to compare the processability of different resins.

Splay Marks: Scan or surface defects on molded part caused by abnormal racing of the melt in the mold.

Splice:  The joining of the ends of rolled material.

Split Finish: A finish defect. A finish which has a crack, or split, across the top surface, extending from the top of the finish downward.

Split Fountain:  Putting more than one ink in a printing fountain to achieve special color effects.

Split-Ring Mold: A mold in which a split cavity block is assembled in a channel to permit the forming of undercuts in a molded piece. These parts are ejected from the mold and then separated from the piece.

Spoilage:  Planned paper waste for all printing operations.

Spot Color:  Single colors applied to printing when process color is not necessary (i.e. one, two and three color printing), or when process colors need to be augmented (i.e. a fluorescent pink headline or a metallic tint).

Spot Varnish: Varnish used to highlight a specific area of the printed sheet.

Spout Pouch: A reclosable or resealable pouch produced with a weld spout and a cap which allows for reclosing, particularly appropriate for liquids.

Spray Can: See Aerosol.

Spray Frosting: The technique of spray coating a glass container to create a frosted, matte translucent appearance.

Spread: 1) A design that encompasses two or more facing pages, i.e. the center spread in the morning newspaper.  2) Literally, spreading the ink around a colored object so that there is no gap between it and the next colored object, i.e. yellow text on a blue background.

Sprue: The feed opening provided in injection molding between the nozzle and cavity or runner system.

Sprue Bushing: A hardened-steel insert in the mold that accepts the nozzle and provides an opening for transferring the melt.

Sprue Gate: A passageway through which melt flows from the nozzle to the mold cavity.

Sprue Lock: The portion of resin retained in the cold-slug well by an undercut. This lock is used to pull the sprue out of the bushing as the mold opens. The sprue lock itself is pushed out of the mold by an ejector pin.

SRP: Shelf Ready Packaging

Stability Testing: The process used to confirm the efficacy of individual medicines for a set time within a given package under elevated humidity and temperature conditions.

Stabilizer: An agent used in compounding some plastics to assist in maintaining the physical and chemical properties of the material at suitable values over the shelf-life of the product.  

Stable Overlays:  A transparent sheet of material, impervious to stretch or shrink, used as part of the finished art.

Stacking Strength: The maximum compressive load a container can bear over a given length of time, under given environmental/distribution conditions, without failing.

Stack Molds: Two or more molds of a similar type that are positioned one behind the other to allow for additional parts to be manufactured during a cycle.

Stack Press:  Flexographic press where the printing stations are placed one above the other, each with its own impression cylinder.

Staining:  When two different color inks touch or overlap each other they create a third color referred to as a stain.

Standardize Practice: a written description of the minimum necessary to meet the intent of policy and standards.

Standard Size: A boxboard sheet 25″ x 50″ in size which is the basis for all board computations.

Stand-Up Pouch: A pouch that has the ability to stand up, sealed on both sides and around the bottom gusset.

Starch: An organic medium added to paperboard to add stiffness and a degree of water absorption resistance.

Starred Roll:  A paper roll exhibiting a “starred” visual effect on the end of the roll, caused by uneven winding-causes fluctuations in reel tension during press runs.

Star Seal: Strongest bottom seal for liners that combines four sections in a star design. Seal maximizes carrying capacity.

Static: An electrical charge built-up in plastic film.

Static Eliminator:  Mechanical devices frequently used by plastic material manufacturers for removing electrical static charges from plastic articles.

Static Neutralizer: In printing presses, an attachment designed to remove the static electricity from the paper to avoid ink set-off and difficulty feeding the paper.

Static Seal: A type of longitudinal seal used in FFS equipment. Overlapping film edges are adhered to one another via a static charge.

Static Shielding: Four layer construction providing Faraday Cage protection. Offers greater protection than conventional anti-static applications.

Stationary Platen: The large front plate of an injection molding press to which the front plate of the mold is secured. This platen does not move during normal operation.  

Stearamide: A slip additive used by most plastic product distributors in polyolefins. It is used in process industries as release agents, antistatic agents, and antifoaming agents.

Stelvin(R): The Stelvin(R) neck finish can be found on some glass wine bottles. It is a screw thread finish designed to accommodate the Stelvin(R) closure, an aluminium cap with a tamper evident breakaway band. Offers product preservation, a modern look and practicality.

Step-and-Repeat:  A procedure for placing the same image on plates in multiple places. Alt:  In photomechanics, the procedure of multiple exposure using the same image by stepping it in position according to a predetermined layout or program.

Stereotype:  Duplicate relief plate used for newspaper printing.

Stet: A proofreader’s mark, written in the margin, signifying that copy marked for correction should remain as it was.

Stickyback:  Double-faced, adhesive-coated material used for mounting elastomeric printing plates to the plate cylinder (flexo).

Stiffness: Without its stiffness, paperboard would not be able to perform its function. Paperboard offers higher stiffness at lower grammage than paper–the same stiffness at about 25% lower grammage. This is one of the factors that specifiers usually consider most when choosing paperboard. The measurable properties normally related to stiffness are bending stiffness, bending resistance, and bending moment. Another property closely related to stiffness is bulk (i.e. grammage in relation to paperboard thickness).

Stippling:  Art work in which a series of dots are used instead of lines.

Stochastic Screening: A digital screening process that converts images into very small dots (14-40 microns) of equal size and variable spacing. Second order screened images have variable size dots and variable spacing. Also called Frequency Modulated (FM) screening.

Stock: A term referring to the materials that go into a sheet of paperboard in the state in which they exist just prior to going through the papermaking machine.

Stock Box: A carton which is manufactured in large quantities in advance of sale and sold in smaller quantities, usually to retailers.

Stock Packaging: Ready-made, generic packaging that one could affix a label to. Stock packaging is produced inexpensively in massive quantities and generally comes in limited standardized sizes and styles. Many companies use stock packaging exclusively as it wouldn’t make financial sense to have their packaging custom made. Examples include bottles of sauces, vitamin jars, beverage bottles, protein powders, can foods, etc.

Stones: A general defect. Small inclusions of refractory or unmelted batch materials.

Stopping Out:  In photomechanics, application of opaque to photographic negatives; application of special lacquer to protect areas on films in dot etching; staging of halftone plates during relief etching.

Strain: In tensile testing, the ratio of the elongation to the gauge length of the test specimen; the change in length per unit of original length.

Streaking:  Not wiping clean, leaving stripes or lines of color on web.

Strength:  Usually refers to intensity of a color of ink.

Strength and Toughness: Strength and toughness are composite terms used to describe a complex combination of the mechanical characteristics of paperboard. Measurable properties normally related to strength and toughness are tensile strength, tearing resistance, delamination strength, and compression strength. These factors are crucial for achieving sophisticated designs, such as embossing or complex structural shapes.

Stress: The force producing deformation in a body, measured by the force applied per unit area.

Stress Concentrators: Abrupt changes in geometry of the part serve as the focus of high stresses. Various means can be devised to relieve the abruptness of the geometric changes and the stress.

Stress Cracking: There are three types of stress cracking, all of which result in the splitting or fracturing of the molding: 1. Thermal stress cracking, caused by prolonged exposure of the part to elevated temperatures or sunlight. 2. Physical stress cracking between crystalline and amorphous portions of the part, when the part is under an internally or externally induced strain. 3. Chemical stress cracking when a liquid or gas permeates the partís surface.

Stress Relaxation: The decay of stress at a constant strain.

Stress-Strain Curve: Curve plotting the applied stress on a test specimen versus the corresponding strain. Stress can be applied through shear, compression, flexure, or tension.

Stretch:  Intensity of color of flexographic ink.

Stretch/Shrink Factors:  Calculations of dimensional change that occur in rubber plate molding and mounting and photopolymer plate mounting when applied to the flexo plate cylinder.

Stretch Wrap: A polymer film used in many applications, especially in wrapping pallet loads to keep them secure.

Striations:  Marks evident on the molded-part surfaces that indicate melt flow directions or impingement.

Strike-On Composition:  Type set by a direct-impression method, or on typewriter composing machines. Also known as cold type.

Strike Through: Penetration of ink through the web in flexo and gravure.

Stringiness: The property of an ink to draw into filaments or threads.

Strings: Strings of material due to poor gate cut off.

Striping:  A printing imperfection observed when the printed copy becomes alternately more or less intense across the web.

Strip Pack: A package used to protect solid dose pharmaceutical products, and to provide relatively inexpensive protection for individual dosages.

Stripped:  When separate pieces of film are taped together to create the complete printing image.

Stripper Plate: A plate that strips a molded piece from core pins or force plugs. The stripper plate is set into operation by the opening of the mold.

Stripping: In printing, ink stripping on the ink rollers is prevented by plastic or copper-coated steel rollers in the ink roller train. In box making, removal of excess board around or in carton blanks – this may be done either by hand or mechanically.

Stroke of Oscillation:  The distance the doctor blade oscillates.

Strong-Bow: Pre-stretched pallet wrap. Once stretched, it has better load retention and lighter weight rolls.

Structural Design: A department that designs and/or programs the folding carton.

Structural Foam Molding: The process of molding thermoplastics articles with a cellular core and integral solid skins in a single operation.

Style: In the Glass and Plastic product types, Style can refer to standard industry names, such as Cylinder, Boston Round, F-Style, Modern Round, Wide Mouth Jar, etc. If a name is not standard industry-wide, Style refers to the sides of the bottle, i.e., straight sided, tapered, etc. In the Closure product type, Style designates standard industry names. If a closure has threads, the Style is Continuous Thread. Other Styles include Dispensing, Child Resistant Closure (CRC), etc.

Styles: Construction variations of the folding carton. Styles may be identified by descriptive names or the proprietary designations of their inventors or manufacturers. In the Federal Specification “Boxes, Folding Paperboard” (PPP-B-566a) styles are listed by Roman numerals with variations in construction referred to as “types” with Arabic numbers, and “classes” with lower case letters

Style Sheet:  A page or group of pages designating the type faces to be used in a design. i.e. Headlines, captions and body text.

Stylus:  A hard pointed pen shaped instrument used in marking, writing, incising, tracing, etc.

Styrene: Styrene is the key building block for styrenic polymers. This includes materials such as Polystyrene, ABS, EPS or Expandable polystyrene, to name but a few. Plastic manufacturers use styrene-based resins to produce a wide variety of everyday goods ranging from cups and utensils to furniture, bathroom, and kitchen appliances, hospital and school supplies, boats, sports and recreational equipment, consumer electronics, automobile parts, and durable lightweight packaging of all kinds.

Subgate: Entrance to the part from the runner located below the parting line. On ejection, the part breaks away from the sub gate.

Sublimable Dyes:  Dyes that have the capacity to move from a solid state to gas and back to a solid without passing through a liquid phase.

Sublimation:  The process in chemistry whereby a solid is volatilized by heat and then converted back into a solid without passing through a liquid phase.

Substance:  The weight, in pounds, of a ream (either 480 or 500 sheets) of paper cut to a given size.

Substance Weight:  A term of basis weight when referring to bond papers.

Substrate: Any material that can be printed, such as paper, plastic, glass, or metal.

Subtractive Primaries: Yellow, magenta, and cyan; the hues used for process color printing inks.

Suck-back: When the pressure on the sprue is not held long enough for the melt to cool before the screw returns. Some of the melt in the cavities or runner system may expand back into the nozzle and cause sink marks on the finished part.

Sulphate Process:  The chemical pulping method that employs caustic soda and sodium sulfide to break down wood into free fiber.  Called sulfate because the sodium salt introduced is sodium sulfate.  Sulfate pulps are also called Kraft.

Sulphate Pulp:  Paper pulp made from wood chips cooked under pressure in a solution of caustic soda and sodium sulphide.  Known as kraft paper.

Sulphite Process:  Any of several chemical pulping methods employing bisulfites of calcium, ammonia, magnesium or sodium.  Bisulfites in solution with water create sulfurous acid, the active ingredient in this process.

Sunken Shoulder: A shoulder defect. A shoulder which is not fully blown.

Supercell: In digital halftone imaging, a combination of subgroups of machine pixels or halftone dots that are handled as a single group.

Surface Finishing: In order to provide a very smooth surface with uniform characteristics for printing and varnishing, the paperboard coating is treated with brush burnishing or gloss calendering. The surface can also be finished with embossing in order to create a special surface texture (e.g. linen structure).

Surface Print: The process whereby the ink is deposited directly onto the outermost surface of the packaging film or material. The process is most commonly used in short run printing. A UV (ultraviolet) coating may be added to provide a hard exterior finish that prevents the ink from flaking or chipping.

Surface Sizing: Surface sizing is done on a section of the paperboard machine and involves the application of a pigmented starch solution to coat the paperboard. Surface sizing binds the fibers to the surface, making the paperboard more uniform and dense.

Surface Strength: Surface strength is the paperboard’s ability to withstand forces applied to its surface. During the printing process the paperboard must be able to resist forces caused by print speed or ink tack. In finishing operations such as creasing or embossing the surface must endure high forces without cracking.

Surface structure: See Smoothness and Surface finishing

Surface Tension: Surface tension is a measure of the wettability of plastic-coated paperboard surfaces. This property influences printability and glueability.

Surprint:  In photomechanics, exposure from a second negative or flat superimposed on the exposed image of a previous negative or flat.

Sustainable Packaging: Packaging that can be used, or recovered and recycled indefinitely, and is not dependent on the availability of finite and non-reproducible resources.

Swatch: A small piece of material cut for a sample.

System Utilization: How effectively time is used during production in regard to the packaging line.


Tab: A small projecting area on a package to assist in the removal of a lid or in the separation of parts.

Taber Unit: Unit of measurement used to determine the stiffness (resistance to bending) of a material such as paper or paperboard.

Tab Gate: A small removable tab, about the same thickness as the molded item, but usually perpendicular to the part for easy removal.

Tab Length: The length of the tape that overlaps the side of a package.

Tacifier: A general term used to refer to cling additives in stretch film

Tack: In printing inks, the property of cohesion between particles; the separation force of ink needed for proper transfer and trapping on multicolor printing presses. A tacky ink has high separation forces and can cause surface picking or splitting of weak papers.

Tackifiers: Additives used to enhance the adhesiveness or bonding ability of a material.

Tagged Image File Format (TIFF):  A file format for exchanging bitmapped images (usually scans) between applications.

Talc: A natural hydrous magnesium silicate, used frequently as an additive in plastic compounds.

Tamper-Evident/Resistant Closure: A sealed closing device for a package that cannot be opened without showing evidence of opening and so is resistant to tampering. May take the form of a tape, overwrap, detachable ring, sealed diaphragm, etc. Incorrectly called “tamper-proof,” as such seals cannot guarantee the avoidance of tampering.

Taper:  To become progressively smaller in thickness, diameter, or width; as in a cylinder or roll.

Tap Switch: An electrical device used to control the amount of voltage introduced to sealing elements.

Target Cost: The estimated cost to accomplish the project contract as defined by the estimate design basis and the project objectives.

T Dimension: The outside diameter of the thread helix on a bottle finish.

Tearing Bond:  A type of bond in which it is necessary to tear fibers of one or the other adhered sheets in order to separate them. At the same time, there is no failure in adhesion or cohesion of the adhesive.

Tear Initiation: The amount of force required to initiate a tear.

Tear Resistance: Also called tear strength, is the measure of how well a plastic material can withstand the effects of tearing. Natural rubber and polyurethane, for example, have high tear resistance. Materials with low tear resistance tend to have poor resistance to abrasion and will quickly fail when damaged.

Tear Strength: The force required to tear apart a material specimen under defined, standard conditions.

Tear Strip:  A narrow ribbon of film, cord, etc, usually incorporated mechanically in wrapper or overwrap during the wrapping operation to facilitate opening of the package.

Tear Test: See Elmendorf Test

Tear Under Finish: A finish defect. A finish which has a small surface section of glass torn from under it.

Telescope Box: A box composed of two separate sections consisting of a tray and a similar-shaped lid. The length and width of the lid are slightly larger than those of the tray so that the lid slides over the tray as follows: full telescoping (the lid fits over the entire depth of the tray) and partial telescoping (the lid fits over a portion of the whole depth of the tray).

Telescoping:  Transverse slipping of successive winds of a roll of material so that the edge is conical rather than flat.

Temper: A measure of the ductility and hardness of steel plate.

Tensile Modulus (Also called modulus of elasticity): The ratio of nominal stress to the corresponding strain below the proportional limit of a material.

Tensile Strength, Break: The maximum stress that a material can withstand without breaking when subjected to a stretching load.

Tensile Strength, Yield: The maximum stress that a material can withstand without yielding when subjected to a stretching load.

Tensile Strength: A paperboard with high tensile strength is generally produced by using chemically processed virgin fibers, preferably long fibers from spruce and pine. The sheet forming process and the multi-ply construction further enhance the tensile strength. This property is measured in terms of the force required to break a 15 mm wide paperboard strip.

Terabyte (TB):  One trillion bytes.

Tertiary Package: Transit Container (e.g. large corrugated case), may also be known as break-pack. See also: Primary Package; Secondary Package

Test Liner: Paper made from either a combination of wood pulp and recycled fiber or entirely of recycled fiber.

Text:  The body matter of a page or book, as distinguished from the headings.

Text Paper:  Grades of uncoated paper with textured surfaces.

Thermal Conductivity: Ability of a material to conduct heat.

Thermal Degradation: Deterioration of the material by heat, characterized a breakdown of the molecular bond.

Thermal Dye Sublimation:  Like thermal printers, except pigments are vaporized and float to desired proofing stock.  Similar to Thermal Dye Diffusion Transfer, or D2T2.

Thermal Printers:  These printers use a transfer sheet that carries ink in contact with the paper or transparency, and a heated printhead

Thermal Shut-Off: Material freezes causing blockage.

Thermal Transfer Printers:  These printers use a transfer sheet that carries ink and is placed in contact with the paper or plastic transparency, and a heated printhead driven by digital data touches the transfer sheet to transfer images to the right positions on the page.

Thermocouples: Temperature sensor for measurement and control. It can also be used to convert a temperature gradient into electricity. These are used on plastic extruder machines.

Thermoelasticity: Rubber-like elasticity exhibited by a rigid plastic resulting from an increase in temperature.

Thermoforming: The process of forming a thermoplastic sheet into a three-dimensional shape by clamping the sheet in a frame and heating until soft and flowable. Differential pressure is then applied to make the sheet conform to the shape of a mold or die positioned below the frame.

Thermography:  A printing process that results in raised type, similar to engraved embossing.

Thermo-Mechanical Pulp:  In papermaking, pulp made by steaming wood chips prior to, and during refining, producing higher yield and stronger pulp than regular groundwood.

Thermoplastic: Material that will repeatedly soften when heated and harden when cooled.

Thermoplastic Elastomers: The family of polymers that resemble elastomers, in that they can be repeatedly stretched without distortion of the unstressed part shape, but are true thermoplastics and do not require curing.

Thermoplastic Screw: The screw in the barrel of the plastic extrusion machine. There are single screw and vented (two-stage/twin) screws. Often screw length is referenced to its diameter as L:D ratio. For instance, a 6-inch (150 mm) diameter screw at 24:1 will be 144 inches (12 ft) long, and at 32:1 it is 192 inches (16 ft) long. An L:D ratio of 24:1 is common, but some machines go up to 32:1 for more mixing and more output at the same screw diameter. Two-stage (vented) screws are typically 36:1 to account for the two extra zones.

Thermoset: A polymer that doesn’t melt when heated. Thermoset polymers “set” into a given shape when first made and afterwards do not flow or melt, but rather decompose upon heating. They are often highly cross-linked polymers, with properties similar to those of network covalent solids, i.e., hard and strong.

Thickness: The thickness of paperboard is of course directly related to its stiffness. But thickness is not the only factor to consider. With a dense paperboard you need higher thickness to achieve the same stiffness compared to a bulky paperboard.

Thinners:  Liquids, solvents and/or diluents, added to fountain ink for the purpose of reducing the viscosity of the ink.

Thin Shoulder: A shoulder defect. A shoulder which has a thin section, characterized by the difference in color between thick and thin glass, or by the appearance of a wave above and below the thin section.

Thixotropy:  The property of a liquid or plastic material that involves a reversible decrease of viscosity as the material is agitated or worked.

Thread: (1) The spiral, raised from around the neck or aperture of a rigid package, or the finish of a bottle or jar to guide and secure the closure, whose inner surface has a complementary form which interlocks with that on the container as the closure is turned. (2) A thin usually textile cord generally used to sew materials together. 3) In a press or coating machine, initial passage of a web between the various rollers or other parts of the machine.

Threads Not Filled Out: A finish defect. A finish with threads or lugs that are not completely blown or pressed to the shape of the cavity in the neck ring.

Three-Piece Can: The most common type of metal can, made of three main components; a side-seamed body and two separate ends. Usually delivered to the canner with one end already double seamed to the body.

Three-Side-Weld Pouch: (Pillow) – A pouch made from two pieces of film, sealed on three sides leaving one side open. These have no gusset.

Throughput: the exact quantity of quality packaged produced in a package run cycle as required by the customer and shipped to the customer.

Thumbhole: A semi-circular or triangular cut made in the sides or ends of cartons to facilitate opening of the package. Semi-circular openings used on multi-packs for inserting fingers to carry the package.

Tie-Bar Spacing: The space between the horizontal tie-bars on an injection molding machine. Basically, this measurement limits the size of molds that can be used on the machine.

TIFF:  See Tagged Image File Format.

Time Scan: Measures the effects of mold and melt temperature and injection time changes on pressure, stress and temperature at the end of flow.

Tin: (1) Noun – A metal with high corrosion resistance, traditionally used as a protective layer on steels. (2) Popular term for a metal can. (3) Verb – To apply tin to a surface.

Tinctorial Strength:  The relative ability of a pigment or dye to impart color value to a printing ink.

Tin-Free Steel (TFS): A raw material for metal cans. Cold-reduced steel sheet made corrosion resistant by a very thin coating of chromium phosphate, chromium /chromium oxide or aluminium.

Tin Plate: A raw material for metal cans. Cold-reduced low carbon sheet, protected by coating on both sides with a very thin layer of tin.

Tints:  A shade of single color or combined colors. Alt:  1) A color of very low strength or intensity, usually made by adding a small amount of color ink or toner to a large amount of extender or opaque white.  2) A lighter shade of ink created by printing a finer dot pattern, but using full strength ink.  A wide gamut of hundreds of shades can be created by surprinting tints of the process colors.

Tissue Overlay:  Usually a thin transparent paper placed over artwork for protection. Used for making color breaks and other printer instructions.

Toggle: A type of clamping mechanism that exerts pressure by applying force on a knee joint. A toggle is used to close and exert pressure on a mold in a press.

Tolerances: The specification of acceptable variations in register, density, dot size, plate or paper thickness, concentration of chemicals, and other printing parameters.

Toner:  Imaging material used in electrophotography and some off-press proofing systems.  In inks, dye used to tone printing inks, especially black. Alt:  1) A highly concentrated pigment and/or dye used to modify the hue or color strength of an ink.  2) Black and colored electrostatic imaging materials used in xerographic copiers and in toner-based proofing systems.

Tone Reproduction: The tonal relationship between all the elements of a reproduction.

Tone Scale: Tone scale is the measurement of all possible tones between 0 and 100% saturation of a certain color.

Tonnage: The measure by which injection molding machines are typically categorized, representing the clamping force of the injection molding machine.

Tool: In injection molding, the term sometimes used to describe the mold.

Tooth: A characteristic of paper, a slightly rough finish, that permits it to take ink readily.

Top and Bottom Drive: A machine that moves the package along using top and bottom belts

Top-Opening Regular Slotted Container: An RSC configured to be filled from the top and stay upright. The flute direction is typically vertical in order to give the box maximum stacking strength.

Top Sheeting: A protective covering put on the top of a load to protect the top from dust, dirt, and other objects that might damage or dirty the load.

Torque – Application, Removal and Stripping: Application torque is the rotational force with which a threaded closure is applied to a container finish during capping. It should be sufficient to ensure seal integrity and tightness between bottle and closure. Similarly, removal torque is the force required to loosen the closure and stripping torque is the force required to override the closure on the container screw threads, thus destroying the seal.

Toughness: See Strength and toughness

Transfer Bead: A projecting bead on the outer surface of some glass containers, usually just below the finish, to provide a surface of engagement for the jaws of handling devices during manufacture.

Transfer Molding: A process of forming articles by fusing a plastic material in a chamber then forcing the whole mass into a hot mold to solidify.

Transfer Roll:  Plain roll in an inking system, rotating in contact with another plain roll, transferring variable amounts of ink.

Transfer Screens:  Halftone screens of different sizes that can be transferred from their original carrier sheet to the artwork by rubbing with a stylus.

Transfer Sheets:  Carrier sheets of type characters, design elements, or halftone screens that release the image when pressure is applied.

Transfer Type:  Type characters of different sizes and styles that can be transferred from their original carrier sheet to the artwork by rubbing with a stylus.

Transient Period: Time required after the package changeout has been completed to get the given interval actual run speed to exceed the 80% of achievable run speed.

Transition Temperature: The temperature at which a polymer changes from a viscous or rubbery condition to a hard and relatively brittle one, or vice versa.

Translucent: Descriptive of a material or substance capable of transmitting some light, but not clear enough to be seen through.

Transmission: Quantity of moisture and/or gas passing through the packaging film or foil over a specific period of time.

Transparent: Descriptive of a material or substance capable of a high degree of light transmission (e.g., glass). Some polypropylene films and acrylic moldings are outstanding in this respect.

Transparent Copy:  A film that light must pass through for it to be seen or reproduced. Alt:  In photography, illustrative copy (such as a color transparency or positive film) which must be illuminated to be seen or reproduced.

Transparent Ink: A printing ink that does not conceal the color beneath. Process inks are transparent so that they will blend to form other colors.

Transverse Direction (TD): The direction parallel to the film width.

Trapping:  In printing, the ability to print a wet ink film over previously printed ink.  Dry trapping is printing wet ink over dry ink.  Wet trapping is printing wet ink over previously printed wet ink.  In prepress, it refers to how much overprinting colors overlap to eliminate white lines between colors. Alt:  The process of closing gaps between different color inks as they appear on the printed page. Trapping color is achieved by use of chokes and spreads.

Trap Print: Trap printing derives its name from the fact that the ink is trapped between the outer layer of material and the substrate. (see also Reverse Printing)

Tray: Usually a shallow open-topped container made of wood, paper board, metal or plastic. As a returnable package, it often used to deliver, for example, baked goods. As a one-way item, the tray is packed inside a carton or serves as a component of packages overwrapped in transparent film. Items packed in trays include meat and dairy products.

Tray Style Carton:  A structure developed from a flat blank comprised of a base and at least three hinge-connected side or end panels, which in turn are connected at the corners by adhesive or mechanical means to form an open top carton.

Treater: Equipment and processes generally used by plastic manufacturers to enhance the surface of inert plastics, such as polyethylene plastic, for more usable means.

Trim: The amount of excess film severed during the sealing process.

Trim Marks:  In printing, marks placed on the copy to indicate the edge of the page. Alt:  Similar to crop or register marks.  These marks show where to trim the printed sheet.

Trim Seal: A seal made by using a sealing wire element.

Trim Size: The maximum width that can be efficiently produced on a paperboard manufacturing machine, printing press or paperboard converting machine, minus an allowance for trimming off edges. The size of something after a trimming operation.

Tub: A rigid container of metal, paperboard or plastic, usually fitted with a lid, and mainly used for packaging viscous products, i.e. butter, margarine, cheese, etc.

Tube: A hollow cylinder. Can be extruded from metal, glass or plastic, or spiral wound from paper or paperboard (Core). Metal and plastic tubes can have flexible walls and one end may be flattened and sealed by crimping or heat sealing. May be fitted with ends or closures; the ends may be clamped, crimped or heat sealed in place. A shoulder with threaded neck for accepting a screw cap may be fitted in one end.

Tube Style Carton: A structure developed from a flat blank comprised of a series of three or more hinge-connected panels, which have the free vertical edges of the outermost panels connected by adhesive or mechanical means to form a carton open at both ends.

Tubular Glass: Containers made from preformed hollow glass tubes. The tubes are cut into desired length, and by heat and pressure they are shaped into the desired configuration. Unlike blown glass, tubular items do not require molds.

Tuck: The end portions of the top or bottom flaps of a folding paper box (carton), which are inserted inside the container to hold the end (top or bottom) flaps in place.

Tuck End Carton: A carton consisting of four or more panels that are folded completely around to make a tube. To close the tube there will be on both ends either tuck flaps, seal and flaps or other type flaps or locks.

Tunnel:  The compartment through which the web passes for final drying after printing.

Turning Bars:  An arrangement of stationary bars on a flexo press, which guide the web in such a manner that it is turned front to back for printing in-line on the reverse side.

Turntable: Machinery that can be used to rotate a pallet in order for the stretch wrap to be applied

Twin-Screw Extruder: Twin screw extrusion used in plastic extrusion manufacturing offers several advantages over single screw extrusion. It has better feeding and more positive conveying characteristics, which allow the extruder to process hard-to-feed materials. In addition, better mixing and a larger heat transfer area offer good control of stock temperatures;  key elements in the extrusion of thermally sensitive materials.

Twin-Wire Machine:  In papermaking, a four-denier paper machine with two wires instead of one, producing paper with less two-sidedness.

Twist-Off Cap (Lug cap): A robust closure system, generally of tinplate; operates on the principle of lugs engaging with a threaded finish on the container. Used only with rigid containers such as glass bottles and jars. Usually provided with a liner to ensure satisfactory sealing.

Two-Piece Can: Made of either steel or aluminium. Has a body and base made by pressing from one piece of metal, with no side seams. There are two principal types, “drawn and wall ironed” (D&I), and “drawn and redrawn” (DRD).

Two-Sheet Detector: A safety device for stopping or tripping the press when more than one sheet attempts to feed into the grippers. At high speed, multiple sheets could smash the blanket or destroy the plate.

Two-Sidedness:  In paper, the property denoting a difference in appearance and printability between its top (felt) and wire sides.

Type Gauge:  In composition, a printer’s tool calibrated in picas and points used for type measurement.

Type I Glass: A borosilicate glass which releases the least amount of alkali. It is commonly used for pharmaceutical or fine chemical products that are sensitive to PH changes.

Type II Glass: A soda lime glass (Type III) that has been de-alkalized by treating the interior surfaces to eat away the alkali on or near the glass surfaces. The undesirable characteristic of Type II Glass is that the treating etches the surface, causing a frosted appearance.

Type III Glass: A soda lime glass and the most common in use. Type III is compatible with most items: food, beverages, common chemicals, etc.

Type NP: Glass General purpose soda lime glass.

Typography:  The style, arrangement or appearance of typeset matter.  The art of selecting and arranging typefaces.


U-Board: A “U”-shaped boxboard configuration of a body and two ends or sides, scored to provide rigidity and facilitate overwrapping of product with flexible packaging material.

UCA (UnderColor Addition): In process color printing, used with GCR, UCA is ink added in shadow areas to increase color saturation.

UCR (UnderColor Removal): In process multicolor printing, color separation films are reduced in color in neutral areas where all three colors overprint, and the black film is increased an equivalent amount in these areas. This improves trapping and can reduce makeready and ink costs.

U-Liner: A protective layer typically made from single wall corrugated in the shape of the letter U.

Ullage: Term for the headspace above the product inside a container.

Ultimate Elongation: In a tensile test, the elongation at rupture.

Ultimate Strength: Term used to describe the maximum unit stress a material will withstand when subjected to an applied load in a compression, tension, flexural, or shear test.

Ultraviolet (UV) Coatings: Coatings which are cured, or dried, by exposure to ultraviolet radiation. These coatings offer excellent gloss, as well as chemical and rub resistance.

Ultraviolet (UV) Inks: Solventless printing inks which incorporate liquid photopolymers that release free radicals on exposure to large doses of ultraviolet light. The radicals cause the ends to polymerize into a dry resin, eliminating the need for drying time.

Unbalance:  The uneven distribution of weight or forces in a roll.  In flexo there are two recognized types of unbalance:  Static and Dynamic.

Uncoated Recycled Board (UCRB): An uncoated paperboard composed of 100% mixed recycled fibers. The color of the material is dependent on what type of recycled fiber is used. Newspaper based fiber yields a light grey color, while corrugated based yields a light tan/brown color. It is slightly cheaper than coated recycled board because of the perceived loss in quality. UCRB is used to package automotive parts, hardware items, and other retail products. UCRB is generally not approved for direct food contact due to the possible post consumer contaminants.

Undercut:   A protuberance or indentation that impedes withdrawal from a two-piece rigid mold. Alt: The difference between the radius of the cylinder bearers and the cylinder body, to allow for plate (or blanket) and packing thickness.

Underflow: The dominant flow of two confronting flows, one over the other. The lesser flow reverses direction, giving poor surface appearance and structural strength. Underflow should be avoided by positioning gates so that the flow fronts meet at the end of filling.

Under Packaging: Insufficient packaging that may result in the loss or failure of the contained product.

Under-Run:  Production of fewer copies than ordered.  (See also Overrun).

Undistorted Artwork:  Artwork that has been prepared without compensation for the distortion that takes place after the printing plate has been mounted on the printing cylinder.

Uneven Distribution: A general defect. Thin and thick areas, especially in the side walls of the ware.

Unidirectional Flow Pattern: Plastic flowing in one direction with a straight flow front throughout filling.

Uniform Cooling Time: Cooling time that is the same throughout the part; avoids warping.

Uniform Quality: All good characteristics and features of graphic paperboard would not be of much value if they were not also uniform. What counts is uniform quality in the finest details, both consistent within a single delivery as well as between different deliveries.

Unit: 1) A large group of bundled or unbundled boxes, banded and/or stretch filmed together for shipment. 2) In multicolor presses, refers to the combination of inking, plate, and impression operations to print each color. A 4-color press has four printing units each with its own inking, plate, and impression functions.

Unitization: Wrapping techniques that protect a pallet load from top to bottom, making all packages in the load one single unit. These techniques are ideal for long distance hauls and less than truckload (LTL) shipments. X-wrapping, Wrapping Low, and Cross Top Wrapping are wrapping techniques that promote the best unitization.

Unitize: To assemble a group of parts, products, or packages into an appropriate unit for handling or sale.

Unitizer: Machine that assembles layers of product, as done by a palletizer.

Unit Mold: A simple mold which comprises only a single cavity without further mold devices, and is used for the production of sample containers.

Unit Weight: Indicated how much one square meter of a substrate weighs in grams (g/m2). See also: Grammage

Universal Product Code (UPC): A computerized method of registering sales information on products identified by the system. Electronic scanners are used to read pre-designated product codes at the point of purchase. This information is instantly fed into a computer which provides pricing information, accumulates inventory data, and synthesizes sales analysis date.

Up:  Printing “two-up” (or three, four, etc)  means printing multiple copies of the same image on one sheet. Determining how many copies fit across a sheet greatly affects pricing.

UPC: Universal Price Code or barcode.

UPC Symbol: A pattern of bars and spaces (which can be electronically read by a scanner) applied to a product container for use in implementing the Universal Product Code system. The symbol contains a numeric code identifying both the manufacturer and product.

UPVC: Unplasticized polyvinyl chloride is a rigid plastic polymer. UPVC is low maintenance and has strong resistance against chemicals, sunlight, and oxidation from water. Rigid PVC can be used for thermoplastic extrusion and is supplied in a variety of colors and strengths. Unplasticised PVC is one of the stiffest polymers at ambient temperatures and is very durable. It is extremely versatile and is used for a wide variety of applications in most industry sectors.

UV Coating:  Liquid laminate, bonded and cured with ultraviolet light.

UV Drying/Curing: See Absorption and drying

UVI: Ultra Violet Inhibitor. Additive extends life of the product in sunlight conditions.

UV Inks: Solventless inks that are cured by UV radiation. UV inks are used extensively in screen printing, narrow web letterpress, and flexographic printing.

UV Printing:  Printing with ultraviolet inks.

UV Stabilizer: Any chemical compound which, when mixed with a thermoplastic resin, selectively absorbs UV rays. It slows down degradation by UV rays, which affects most plastics.


Vacuum Back:  A vacuum mounted to the top or back of a process camera with that can be used to hold photographic paper or film in place during exposure.

Vacuum Closure: Any closure equipped with a liner capable of holding a vacuum.

Vacuum Forming:  The process of heating a plastic until it is soft, placing it over a mold, and then molding it to form by means of a vacuum.

Vacuum Frame:  In platemaking, a vacuum device for holding copy and reproduction material in contact during exposure.

Value analysis: a systematic approach to simplification and standardization of products so that they provide needed value at minimum cost.

Valve Gating: A type of gate where a pin is held in the gate or channel by spring tension. As the injection stroke moves forward, this gate compresses the plastic in the runner. When this pressure build-up is sufficient to overcome the spring tension, the pin is then pushed back and the fast decompression of the melt fills the cavity at extremely high speed.

Varnish:  A thin, protective coating applied to a printed sheet for protection or appearance.  Also, in ink making, it can be all or part of the ink vehicle. Alt: A clear liquid applied to printed surfaces for looks and protection, although UV coating looks better.

Vat-Lined Board: Cylinder boards which have one or both of the surface linings composed of furnish different from the inner plies. They may be colored.

VCI Film (Vapour Corrosion Inhibitor): Vapour Corrosion Inhibitor for packaging products in the form of a plastic film. A significant breakthrough in protective packaging technology. It offers a new concept in production protection without the need for rust preventative coatings. It provides protection for aluminum alloys and copper, while providing excellent protection for ferrous metals, steel, and stainless steel. It protects products such as tools, spare parts, components, bin/box liners, motor and mechanical controls, electrical equipment and controls, long tubular products and pipes, interleaving, etc. Metals Protected: Copper, Brass, Aluminum, Steel, Tin, Silver Iron, etc.

Vehicle: In printing inks, the fluid component that is used as a carrier for the pigment.

Vellum:  High quality translucent paper used for tracing.

Vellum Finish:  In papermaking, a “toothy” finish, relatively absorbent for fast ink penetration.

Velox:  A black and white photographic print of very good quality that can be used as part of the artwork and later reproduced for printing plates.

Vent: In a mold, a shallow channel or minute hole cut in the cavity to allow air to escape as the material enters and to facilitate ejection of the molded part from the cavity.

Vented Barrel: Special barrel unit with a vent port over the compression section of the screw to permit the escape of gases prior to injecting melt into the mold. Often used when molding moisture-sensitive resins.

Verso:  The left-hand page of an open book.

Vertical Adjustment:  A method of analysis that depends upon a measurement of the volume of a standard solution consumed in a titration.

Vertical Flash Ring: The clearance between the force plug and the vertical wall of the cavity in a positive or semi-positive mold. Also, the ring of excess melt which escapes from the cavity into this clearance space.

Vertical Reciprocating Press: Press in which both the form and impression cylinders move up and down in a reciprocating motion.

Vibration: A mechanical phenomenon whereby oscillations occur about an equilibrium point. The oscillations may be periodic such as the motion of a pendulum or random such as the movement of a tire on a gravel road.

Vibration Test: A specific test to determine the ability of a container to protect its contents from vibration at varying amplitudes and frequencies. See also: Shock test

Vicat Softening Point: The temperature at which a flat-ended needle will penetrate a specimen under a specific load using a uniform rate of temperature rise.

Vignette Halftone:  An illustration in which the background fades away gradually until it blends into the unprinted paper. Alt: A halftone whose background gradually fades to white.

Vinyl:  Informal generic term for any of the vinyl resins, film, or other products made from them.

Vinyl Plastics:  Plastics based on resins made from vinyl monomers, except those specifically covered by other classifications such as acrylic and styrene plastics.  Typical vinyl plastics are polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, and polyvinyl butyryl, and copolymers of vinyl monomers and unsaturated compounds.

Virgin Fibers: Using virgin fibers (wood fibers) to produce graphic paperboard means using a natural raw material. Virgin fibers are by nature strong and elastic. They are also pure and of known origin. All virgin fibers share some natural properties to a greater or lesser degree, and there are also other specific properties associated with fibers of particular wood species.

  • Basically, the choice of virgin fibers is between long fibers (spruce and pine) and short fibers (birch). Long fibers are stronger and more elastic, while the short ones are stiffer. The fiber characteristics are also influenced by the method of pulping (chemical or mechanical pulp).

  • The natural properties shared by all virgin fibers with regard to pulping and board making are:

  • The ability to bond together at points of contact as the web dries. This is known as consolidation of the web, and it provides the strength properties of the paperboard sheet.

  • The capacity to be modified by processing

  • The flexibility, shape and dimensional features that enable the fibers to form a uniform interlaced network

Viscoelasticity: This property, possessed by all plastics to some degree, dictates that while plastics have solid-like characteristics such as elasticity, strength and form-stability, they also have liquid-like characteristics such as flow depending on time, temperature, rate and amount of loading.

Viscometer:  Instrument used to measure the viscosity of ink, varnish, or other solutions.

Viscosity: Viscosity is a measure of the inner friction of inks and varnishes. A highly viscous ink is more adhesive and tacky than an ink of low viscosity.

VMPET: Vacuum Metallised PET film. It has all the beneficial properties of PET film, plus  improvement in terms of oxygen and water vapour barrier properties.

Void: An unfilled space within a solid material.

Vulcanization:  A curing process in which the physical properties of rubber are changed.


Waist: The central portion of a container which has a smaller cross-section than the adjacent areas.

Warm Color:  In printing, a color with a yellowish or reddish cast.

Warpage: Distortion caused by nonuniform internal stresses.

Wash Board: A general defect. A series of horizontal waves or folds on the side of the bottle. Wavy Appearance A general defect. Irregular surface on either the inside or outside of the container.

Washup: The process of cleaning the rollers, form or plate, and sometimes the ink fountain of a printing press.

Waste: A term for planned spoilage, such as the paper trimmed from a sheet to create bleed.

Water Absorption: The amount of water absorbed by a plastic article when immersed in water for a stipulated period of time. All plastics will absorb moisture to some extent.

Water Based (inks/coatings): see Aqueous (inks/coatings)

Water Bath: Used during the extrusion process to cool plastic extrusions.

Water Break:  The appearance of a discontinuous film of water on a surface, signifying nonuniform wetting and usually associated with surface contamination.

Waterless Printing: In offset, printing on a press using special waterless plates and no dampening system.

Watermark:  A distinctive design created in paper at the time of manufacture that can be seen by holding the paper up to a light.

Water-Tight: That quality of a container or pack­age by which it prevents the passage of liquid water either into or out of the package.

Water White: A grade of color which looks like clear water.

Wax Cascaded: Combined board that has been treated by cascading molten paraffin wax or wax blend over vertical box blanks ensuring that it flows down the flutes and over the facings.

Wax Curtain-Coated: Combined corrugated board that has had its surfaces coated on one or both sides with a molten wax blend.

Waxing: The application of paraffin to printed board or carton blanks as a preservative coating resulting in a high-gloss or impregnated finish.

Wear In (seat):  The act of breaking in a rotating doctor blade by applying pressure against the cylinder without printing.  

Weathering: The attack on glass surface by atmospheric elements.

Web: A continuous sheet of paperboard or other flexible material coming from the machine which produces it. It may be slit and rewound into rolls or cut into sheets. Also refers to belt or blanket on which boxboard is conveyed through papermaking machines. Roll stock is used on some printing and converting equipment.

Web Guide:  Device that keeps the web traveling straight and true through the press.

Web Press:  The name of a type of press that prints from rolls of paper. Alt:  A high speed printing press that prints on both sides of a continuous roll of paper.  Web presses are used for high volume printing such as newspapers and magazines.

Web Printing: The production of printed goods such as flexible packaging from rolls of paper that are passed through the press as one continuous web.

Web Strength:  A measure of the physical strength properties of paper when saturated with water. Expressed in terms of wet tensile-strength, wet bursting-strength, etc.

Web Tension: The amount of pull or tension applied in the direction of travel of a web of paper by the action of a web press.

Welding: Increasingly popular side seaming method for metal cans. No lead is used; welded seams can be either lapped or butted.

Weld Line: Where melted material flows together during molding to form a visible line or lines on a finished part; may cause weakening or breaking of the component.

Well Cap: A closure for a container in which there is an interior recessed opening into which an applicator may be affixed.

Wet Strength Board: A specially treated board, usually kraft, that is resistant to moisture. Wet strength board is often used for beverage carriers, frozen foods, or in applications where the board will be exposed to excessive amounts of moisture, condensation, etc. (see “Carrier Board”)

Wetting:  Surrounding minute particles of pigment with resin solutions during ink-making.

Wetting Agent:  A substance that reduces the surface tension of a liquid, thereby causing it to spread more readily on a solid surface.

Whiskers:  Hairy edges of shadow areas caused by static electricity.

Whiteness: The whiteness of the paperboard is crucial for achieving perfect reproduction of illustrations and photographic images in true colors. In addition to the degree of whiteness itself, the measurable properties normally related to whiteness are brightness and opacity. Whiteness depends on both the whiteness of the baseboard (made from bleached chemically pulped virgin fibers) and the coating (white-pigmented, smooth, and well finished).

White Vat: Recycled paperboard with white liner on one side, kraft liner on other.

Wide Mouth (Finish): Any container having an opening roughly half of the diameter of the container to almost the full diameter size of the container.

Wide-Mouth Bottle/Jar: A glass or plastic container with a finish or opening which is large relative to the diameter of the body.

Widow:  In composition, a single word in a line by itself, ending a paragraph, or starting a page. Frowned upon in good typography.

Wind: The direction in which the film or shrink film is wound on the core.

Winder Wrinkles:  A paper defect caused by a hard spot on the winder reel.

Winding:  The process of transferring paper from the master machine roll to rolls suitable for use on a press.  Also called rewinding.

Window: A die cut opening in a carton blank which provides visibility of contents, usually covered with a transparent film. Sometimes referred to as an aperture.

Wire Edge: A finish defect. A finish which has excessive glass projecting upward from the inside edge of the finish (similar to an overpress) except that it does not extend above the sealing surface. It is sharp and could chip.

Wire Mark:  The impression left in a web of paper by the wire of a fourdrinier machine.

Wire-O:  A bindery trade name for mechanical binding using double loops of wire through a hole.

Wire-O Binding:  A method of wire binding books along the binding edge that will allow the book to lay flat using double loops.  (See Wire O).

Wisps: Similar to stringing, but smaller in size. These also may occur as slight flashing when the mold is overpacked or forced open slightly. Mold-parting-line wear or misalignment can also cause wisps.

With The Grain:  Folding or feeding paper into the press or folder in a direction parallel to the grain of the paper.

Woodcut:  An illustration in lines of varying thickness cut in relief on plank-grain wood for the purpose of making prints.

Work and Tumble:  Printing one side of a sheet and then turning it over from the gripper to the tail (end to end turn) to print the second side using the same side guide and plate.

Work and Turn:  Printing one side of a sheet and running it over from left to right (side to side turn) using the same side guides and plate for the second side.

Wove Paper:  A paper having a uniformed unlined surface with a smooth finish.

Wrap-Around Blank: A scored and slotted sheet of corrugated fiberboard that is formed into a box by folding it around its contents. The user makes both the flap and joint closures.

Wraparound Plate: In rotary letterpress, a thin one-piece relief plate that is wrapped around the press cylinder as an offset plate is mounted. It can be used for direct or indirect (offset) printing.

Wrap Net: Netting pallet wrap. Knitted pallet wrap that holds a load together but also allows air to circulate throughout the pallet.

Wrapping Machine: A device that wraps a flexible material, such as plastic film, around a product or group of products.

Wrinkle: 1) In glass containers, a general defect such as a large fold on the outside of the bottle. Also called “lap”. 2) In inks, the uneven surface formed during drying.

WVTR: Water Vapor Transmission Rate (also known as MVTR- Moisture Vapor Transmission Rate,) is the rate which moisture vapor can permeate through a structure and into a dry atmosphere on the other side. It is recorded in units of gm/100 inches square / 24 hour (g/m2/24 hr). WVTR depends on the gauge of the structure, the materials used in the structure, and the quality of the materials used. Vapor can pass through channels in the seals, holes, tears, or imperfections in a package.


Xerography: An electrophotographic copying process that uses a corona-charged photoconductor surface, electrostatic forces, and dry or liquid toner to form an image


Yellow: Hue of a subtractive primary and a four-color process ink. It reflects red and green light and absorbs blue light.

Yellowness Index: A measure of the color on the yellow scale.

Yield: The amount of stretch a film withstands without interfering with the performance of other properties, like tear and puncture resistance.

Young’s Modulus: The ratio of tensile stress to tensile strain below the proportional limit.


Zahn Cup:  A device for measuring viscosity.

Zip Top Pouch: A reclosable or resealable pouch produced with a plastic track in which two plastic components interlock to provide a mechanism that allows for reclosablility. AKA: Ziplock

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