Glossary




	GLOSSARY OF INK AND PRINTING TERMS

A	B	C	D	E	F	G	H	I	J-K	L
M	N	O	P	R	S	T	U	V	W	Y-Z

Abrasion: the process of wearing away the surface of a material by friction.

Abrasion Resistance: the ability to withstand the effects of repeated rubbing and scuffing. Also referred to as rub or scuff resistance.

Absorption: penetration of one substance into another such as ink into paper.

Acetate: a family of solvents also known as esters. e.g., normal propyl acetate.

ACGIH: American Conference of Governmental Industrial Hygienists Inc. is an organization open to all practitioners in industrial hygiene, occupational health, environmental health or safety.

Acid: a compound which yields hydrogen ions in solution in water; has a corrosive action on many materials, sour in taste, and reddens litmus paper. Concentration stated in terms of pH values; 7 is neutral, lower values indicate acidity. The lower the value, the greater the acidity.

Acid-free Paper: Paper made from pulp containing little or no acid so it resists deterioration from age. Also called alkaline paper, archival paper, neutral pH paper, permanent paper and thesis paper.

Acrylic: A general chemical term of a particular family of thermoplastic resins based on acrylic acid and its derivatives.

Additive Color: color produced by light falling onto a surface, as compared to subtractive color. The additive primary colors are red, green and blue.

Adhesion: the "sticking" together of dissimilar materials, e.g.: adhesion of ink to paper or film.

Adhesive: any material which is applied to one or both surfaces to form a bond between the two.

Agglomerate: a cluster of undispersed particles, often in reference to pigment particles.

Aggregate: a chain of undispersed particles or clusters, often in reference to pigment particles.

Agitation: a stirring action; set in a violent or irregular motion.

Alcohols: a group of organic solvents widely used in the flexographic field. e.g. methanol

Aliasing: The ragged, stairstep edges on slanted or curved lines, or on boundaries between colors, made using a computer. The effect can be lessened (anti-aliasing) through hardware, with a high resolution output device, or through software (Adobe Photoshop, Jag II).

Aliphatic solvents (hydrocarbons): solvents obtained by fractionation of crude petroleum oil. Examples are VM&P naphtha, gasoline and kerosene. Frequently used as part of the solvent mixture in co-solvent and polyamide type flexo inks, in conjunction with Buna-N type plates and rollers; tend to swell natural and butyl rubber.

Alkali: chemical agent, generally soluble in water, capable of neutralizing acids. Usually caustic,; pH of 7 is neutral, up to 14 indicates degree of alkalinity; base.

Ambient Temperature: term used to denote the temperature, pressure and other characteristics of the surrounding air.

Anhydrous: free from water.

Anilox roll: a mechanical or laser-engraved steel and chrome plated metering roll used in flexo presses to meter a controlled film of ink over the substrate. Volume of ink deposited is determined by the cell count, dimension of the cell and configuration of the cell-wall engraving.

Antifoam: an additive used in ink that prevents or eliminates foaming of a liquid or "breaks" foam already formed. See defoamer.

Antioxidant: a substance which prevents or reduces the rate of oxidation due to exposure of the material to air or oxygen.

Antiskid varnish: a generally clear resin coating formulated and applied to flexible packaging to retard slippage during stacking and handling.

Aromatic solvents: unsaturated hydrocarbon solvents; possess excellent solvent properties.

A.S.T.M.: American Society for Testing Materials. Their website is www.astm.org

Azeotrope: a mixture of two or more liquids whose vapour upon evaporation has the same composition as the liquid.

Base: often used to refer to a full strength ink. See Alkali. A very concentrated dispersion of pigment/binder; subsequently mixed to produce the desired end product.

Basis Weight: In the United States and Canada, the weight, in pounds, of a ream (500 sheets) of paper cut to the basic size. Also called ream weight and substance weight (sub weight). In countries using ISO paper sizes, the weight, in grams, of one square meter of paper. Also called grammage and ream weight.

Bind: To fasten sheets or signatures and/or attach covers with glue, wire, thread, or other means. Binding creates the final product, such as a report, book, or magazine, and is one of the last steps in production.

Binder: the adhesive component, or components, of an ink. Normally supplied by the resin. The components in an ink film which hold the pigment to the printed surface.

Bit map: Computer image made up of dots (pixels). Each dot represents one bit. For high-quality publishing, bit map refers primarily to a graphic image as it appears on screen. Bit map graphics, when printed, have a distinctly "computerized" look to them, as they suffer badly from aliasing.

Blanket: Rubber-coated pad, mounted on a cylinder of an offset press, which receives the inked image from the plate and transfers it to the surface to be printed.

Bleach: refers to the method of measuring tinctorial strength of an ink or concentrate. Usually accomplished by mixing a small portion of ink ( or concentrate) with a large amount of white and evaluating the tinting strength of an ink versus a control standard.

Bleed:
1.the tendency of an ink to exhibit varied solubility in a material such as alcohol, paraffin wax, soap, etc. May also refer to slight solubility with resulting transfer of the ink onto the stock on which the ink is printed.
2. Printing that extends to the edge of a sheet or page after trimming. To ensure ink coverage to the bleed edge, bleed materials should extend at least 1/8 inch beyond the trim size of the publication.

Blend: a mixture, such as a mixture of solvents or inks.

Blocking: the sticking together of the surfaces of printed materials when they are in contact with one another.

Blush: the whitening or clouding of an ink or coating due to the condensation of water on the film surface during the drying process. For n/c based inks, referred to as "souring".

Body: refers to the viscosity or flow, characteristics of an ink or vehicle.

Boiling Point: the temperature in which a liquid boils. Can also be used to determine drying speed. Some solvents do not have a precise boiling point but rather a boiling range.

Bond paper: Category of paper commonly used for writing, printing and photocopying. Also called business paper, communication paper, correspondence paper and writing paper.

Brightness: the quality of whiteness intensity as reflected from the printed or unprinted surfaces.

Buna-N: a synthetic rubber 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).

C1S and C2S: Abbreviations for coated one side and coated two sides. The lack of coating on C1S makes writing on the uncoated side much easier.

Caking: the build-up of dried ink upon rollers and plates.

Card Stock: A stiff or rigid paper stock. Card (also referred to as Cover) stock is often used for post cards, catalogue covers and other items which require rigidity. Card stock is usually described by a "Point" size. Point designations state the thickness of the sheet in thousandths of inches (0.001"). For example, 10 pt card is 0.010" thick, 12 pt is .012" and so on. Card stock can also be described by pound weights. Standard US pound (#) weight is determined as the weight of 500, 20" x 26" sheets. (Text stock is measured differently than card and assumes 500 sheets of 25" x 38" to determine pound weight).

Cast-coated Paper: High gloss, coated paper made by pressing the paper against a polished, hot, metal drum while the coating is still wet.

Catalyst: a substance which alters the velocity of a reaction between two or more substances without changing itself in chemical composition.

Cell post: the point at which the cell walls of four adjacent etched cells in an anilox roll meet, forming a common post which braces and adds strength to the walls.

Cellophane: transparent flexible sheeting consisting of regenerated cellulose plus plasticizers with or without functional coatings such as moisture-proof, etc.

Cellosolve® (Union Carbide Corp.): Trade name for ethylene glycol mono-ethyl ether (glycol ether EE) which is used as a retarding solvent in flexographic inks.

Centipoise: a measure of viscosity, conveniently and approximately defined as the viscosity of water at room temperature.

Central impression (CI) 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 in to the central impression cylinder for printing and are arranged around its circumference,

Chalking: a condition of a printing ink in which the pigment is not properly bound to the stock and can be easily rubbed off as a powder.

Chroma: the strength or intensity of a color.

CMYK: Cyan, Magenta, Yellow, Black--printing ink colors for process color reproduction.

Coated Paper: Paper with a coating of clay and other substances that improves reflectivity and ink holdout. Mills produce coated paper in the four major categories cast, gloss, dull and matte.

Coating: the outer covering of a film or web. The film may be one-side coated or two-sides coated.

Coefficient of Friction (COF): measure of slip properties between two surfaces.

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

Color Balance: Refers to amounts of process colors that simulate the colors of the original scene or photograph.

Color Bars: Patches of solid, patterned, and tinted inks on the tail edges of press sheets. These quality control devices permit the measurement of variables such as color balance and registration, trapping, print density, dot gain, and slur.

Color burn-out: see fugitive.

Color Key: Brand name for an overlay color proof. Sometimes used as a generic term for any overlay color proof.

Color separation: Technique of dividing continuous-tone color images into four film halftones ready for stripping, proofing, and platemaking for four-color process printing.

Colloid: a system that is neither a solution nor a suspension. A substance where the particles containing the molecules or aggregates of molecules, do not settle (or do so very slowly).

Colorant: The material in an ink which gives it color; may be a pigment, dye or a combination of the two.

Color fastness: see lightfast, fugitive.

Color gamut: The entire range of hues possible to reproduce using a specific device, such as a computer screen or four-color press. Understanding the color gamut of different devices is imperative to achieve the color on press that you had hoped for. The computer screen can show a different range of colors than a press can print. Spot color inks have a much wider color gamut than process color. The human eye can perceive an extraordinary gamut.

Colorimeter: An instrument used to measure color the way the eye sees it.

Color separation: The process of separating color originals (photos, transparencies, illustrations) into the component colors used in color process printing: cyan, magenta, yellow and black.

Color standard: An ink wet sample or printed proof, to which another, similar material is compared.

Comet: extraneous ink film deposited on the substrate in the shape of a comet. Caused by a foreign particle freeing itself from under the doctor blade.

Compatible: refers to the ability to mix differing solutions or materials together as a homogenous mixture, without resulting in "kick-out" or haziness.

Concentrate: a higher strength version of a base by design. Usually made to add to an ink or solution to increase pigment percentage - hence, the strength.

Consistency: refers to the general body characteristics of an ink.

Contamination: matter which is foreign to or damaging to the product or substance in which it is contained. Impurity.

Continuous-tone: Artwork that is not made up of a printable dot pattern (halftone). An original photograph is continuous-tone.

Corona Treater: A tool that emits an electrical discharge to the surface of a stock (normally films) rendering the stock more receptive or "wettable" to the ink.

Corrosion: Deterioration of a material by chemical action, usually as a result of galvanic, acid, or alkali action, oxidation of metals, etc.

Co-Solvent: One of two or more solvents in a mixture which together, dissolve a solid. (e.g., polyamide resin).

Cover Stock: see Card Stock

Coverage:
1. dry weight of ink or coating used per unit area
2. in printing, the ability to obtain a complete opacity, eliminating the evidence of the base material's color.

Cratering: Thin or bare spots in a coating film which have the appearance of pock marks.

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

Crinkle: wrinkle/wad film severely to determine ink flexibility.

CTP: Computer to plate technology.

CTFP: Computer to flexo plate technology.

Cure (or curing): a conversion by chemical reaction of a wet coating or printing ink film to a solid film.

Curl: distortion of the unrestrained sheet due to differences in structure or coatings from one side to the other.

Cut: to dilute an ink, lacquer or varnish with solvents or with clear base; to thin.

Cyan: One of the four process colors. Also known as process blue.

Dart: similar to comet, described earlier in the glossary

Defoamer: an additive to an ink that prevents or eliminates the foaming of an ink.

Deflocculation: the dispersion of pigment clusters to smaller units in an ink; the reverse of flocculation.

Delamination: the partial or complete separation of the layers of a laminate.

Denatured: to make an alcohol unfit for drinking by adding an obnoxious substance without impairing its usefulness.

Densitometer: instrument that measures reflected or transmitted light. Used as a control instrument to check the uniformity and consistency of print color.

Density: the mass of a unit volume; opacity; color strength.
1. Regarding ink, the relative thickness of a layer of printed ink.
2. Regarding color, the relative ability of a color to absorb light reflected from it or block light passing through it.
3. Regarding paper, the relative tightness or looseness of fibres.

Die-cut: (verb) to punch out with a sharp tool. (noun) Gash, slit or notch left from punching out operation. To cut irregular shapes in paper using a metal die.

Digital Proofing: Page proofs produced through electronic memory transferred onto paper via laser or ink-jet.

Diluent: a liquid having no solvent power in itself used to dilute or thin an ink; not having a solvent action.

Dispersion: a uniform distribution of solid particles in a vehicle by either mixing or milling.

Doctor Blade: a thin flexible blade mounted parallel to and adjustable against an anilox roll, for the single purpose of scraping off excess ink to meter a consistent ink film.

Doctor Roll: the fountain roll in a flexographic press.

Dot Gain: the increase in the size of a dot (of ink) from the film to the printed stock. Phenomenon of halftone dots printing larger on paper than they are on films or plates, reducing detail and lowering contrast. Also called dot growth, dot spread and press gain. The type of ink and paper can affect the amount of dot gain dramatically. Newsprint suffers from heavy dot gain due to the coarseness of the paper fibre.

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

Dpi: Dots per inch. Referring to the output resolution of a device like a laser printer, ink jet printer or imagesetter. Devices can range from low resolution (300 dpi laser printer) to very high resolution (2400-4000 dpi imagesetter). Generally, the higher the resolution, the higher the quality of the output.

Drawdown: a swatch of color made by the spreading of several droplets of ink across a stock for visual analysis. Sample of inks specified for a job applied to the substrate specified for a job. A simple method of comparing two or more wet samples on ink against a standard sample. Also called pulldown.

Dry Offset: Using metal plates in the offset printing process, which are etched to .15mm (.0006 in) creating a right reading plate, printed on the offset blanket transferring to paper without the use of water.

Durometer: refers to the measure of rubber "hardness".

Dwell: the time interval during which elements remain in contact or in a pause position.

Dyne Level: level in which a product's surface energy is located at. Usually achieved by using a dyne pen or by solution.

Dyes: colored substances usually differing from pigments in their solubility into various solvents; in general, rather fugitive.

Efflux cup: see Zahn cup.

Emulsion: a type of mixture (colloidal dispersion) wherein two or more immiscible (or unmixable) materials are held together in a homogenous mixture by the action of a third agent. The term "emulsifying agent" is applied to the material which is added to hold the emulsion.

Engraved Roll: see anilox roll.

E.P.A.: the Environmental Protection Agency, charged by the Clean Air Amendments of 1970 to the Air Quality Act of 1967 with establishing minimum air quality standards which must be incorporated in regional state standards. These standards are essentially similar to those first promulgated by the Los Angeles region of California in their Rule 66.

Ester: a group of solvents made by reacting an acid with an alcohol, e.g., ethyl acetate, isopropyl acetate, normal propyl acetate.

Ethyl Cellulose: a film former used in the manufacture of gravure and some flexo inks and lacquers.

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

Extenders: materials used to weaken, or extend, a fountain ink. Usually in the form of an extending varnish or a transparent white.

Extrusion: the production of a continuous film by forcing hot, thermoplastic material through an orifice.

Exudation: migration of an ingredient in a material or product to the surface.

Fadeometer: instrument used to measure the lightfastness of a printed ink, stock or film.

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

False Body: see thixotropic.

FDA: Food and Drug Administration.

F.T.A.: Flexographic Technical Association.

Feathering: undesirable irregular edges around a print.

Fill-In: generally referred the open portions of small type and halftones filled by ink.

Film:
1. The material produced by prepress houses to allow a printing plate to be made for press. It takes the form of thin sheets of plastic, at first glance looking like acetate sheets, with a negative image of the artwork on it. Film can hold a higher resolution than paper and produces a completely opaque black that is necessary for the photographic process for producing printing plates.
2. Polymer-based ( plastic) continuous roll substrate.

Film Former: a type of resin with qualities of forming a tough, continuous film, usually refers to such plastics as nitrocellulose, vinyl, etc.

Finish: refers to the degree of gloss or flatness of a print or surface.

Flammable: capable of burning. (same as inflammable)

Flash Point: the lowest temperature at which a solvent vapour may be ignited.

Flat: see matte.

Flexography: a method of direct rotary printing. Usually resilient raised image printing plates, affixed to variable repeat plate cylinders, inked by a roll or doctor-blade wiped anilox rolls, carrying ink to virtually any type of substrate. Formerly known as Aniline printing. Abbreviated flexo.

Flocculation: the aggregation of pigment particles in the ink to form clusters or chains. May result in loss of color strength or hue.

Fluorescent: the ability of a fluorescent pigment to emit radiation as a visible light source resulting from and occurring only during the absorption of radiation from another light source.

Foil: term applied to very thin sheets of metal, such as aluminium foil.

Fountain: a pan or trough on a flexo press in which the fountain roller revolves to pick up the ink.

Fountain Solution: Mixture of water and chemicals that dampens a lithographic printing plate to prevent ink from adhering to the non-image area. Also called dampener solution.

Four-Color Process: printing with yellow, magenta, cyan and black, using screens to give an optical effect of all colors and hues in a composite picture.

Fugitive: refers to a dye or pigment having very poor lightfastness.

Gas chromatograph (G.C.): an analytical instrument capable of determining with great accuracy the composition of volatile solvents and oils and of determining their residual presence in inert materials such as paper, board or films.

Gel: a state or condition in which an ink or vehicle has a jelly-like consistency.

Ghosting: the appearance of a faint image of the design being printed in area which are not intended to receive that portion of the image.

Glass Transition: the transition temperature range (relatively small for most polymers) within which an amorphous polymer changes from a rubbery or viscous to glass-like (brittle) state. Syn: second order transition

Glass Transition Temperature (Tg): temperature at which the noncrystalline portion of the polymer is transformed from a tough, rubbery material to a brittle, glass-like material.

Gloss: the ability of a surface to reflect light. Subjective term used to describe the relative amount and nature of mirror-like (specular) reflection

gloss is measure quantitatively to the arbitrary value of 1000 for a perfect mirror. Polished plate glass, which on that basis has a gloss value of about 100, is used as a working standard.

Type¹

60° Gloss

85 ° Gloss

Description

I

0-10

0-15

flat

II

0-10

15+

high sheen flat

III

10-25

Eggshell

IV

25-40

Low semigloss

V

40-55

(regular) semigloss

VI

55-70

High semigloss

VII

70-85

(regular) gloss

VIII

85+

High gloss

(1) This numerical gloss category system was developed for consideration by ASTM Subcommittee D01.42 on Architectural Finishes.

Gloss meter: an instrument used to measure the gloss intensity of a surface.

Gravure: a printing process in which the printing areas are below the non-printing surface. These recesses are filled with a liquid ink with the surplus removed from the non-printing areas by the doctor blade before the paper 'sucks' the ink from the cells. Also called photogravure (UK) and rotogravure (US).

Gray Balance: Printed cyan, magenta and yellow halftone dots that accurately, reproduce a neutral grey image. Used as a quality control measure for achieving proper color balance.

Grind: to wear down a substance through mechanical means, into fine particles or fragments by friction.

Grind Gauge: a tool used to measure or determine, the grind or "fineness" of a substance's size. Usually in microns.

Halftone: photographic image formed by a pattern of discrete dot sizes. Dots vary in area and shape but have uniform density. Creates the illusion of continuous tone when seen at a distance.

Halo: an undesired peripheral outline of the printed image.

Handproofers: a tool manufactured to simulate the transfer of a 2 roll system flexographic printing press. Used to drawdown proofs of ink.

Heat seal: a method of uniting 2 or more surfaces by fusion, either of the coatings or the base materials, under controlled conditions of temperature, pressure and time (dwell).

Helio-Klischhograph: a method of engraving rotogravure cylinders by the use of an electronic scanning system which transmits a signal modulated by the density of a positive copy to a diamond cutting head effecting the engraving mechanically rather than by chemical etching.

Hickey: spot of dirt or dried ink on plate or blanket which shows in printing Often appear in areas of solid ink coverage as dark specks surrounded by light rings of non-printed stock.

Highlights: Lightest portions of a photograph or halftone, as compared to midtones and shadows.

Homogeneous: a mixture blended to a smooth texture, sometimes made miscible by the addition of another product.

Hue: the characteristic by which one color is distinguished from another ; its position in spectral or a chromatic scale.

Hot rub resistance: resistance to abrasion or color bleed of a print when it is subjected to hot irons used for sealing , of primary importance in some package applications.

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 per cent of moisture relative to the maximum which air, at any given temperature, can retain without precipitation.

Hydrocarbons: materials composed entirely of carbon and hydrogen. General term for family of petroleum solvents. see Aliphatic solvents.

Hydrometer: an instrument used for measuring the specific gravity of a liquid or a solution; may be used as an acid in evaluating and controlling the viscosity of fountain ink or varnish mixtures, by indicating the relative ratios of base ink and solvents, where their specific gravities are markedly different.

Hygroscopic: the ability of a material to absorb or otherwise take up moisture from the surroundings.

Impression: the image transferred from the printing plate to the substrate.

Impression Cylinder: Cylinder, on a press, that pushes paper against the plate or blanket, thus forming the image. Also called impression roller.

Inflammable: capable of being burned; easily set on fire (same as flammable).

Inhibitor: a compound (usually organic) that retards or stops a chemical reaction such as corrosion, oxidation or polymerization.

Ink Jet Printing: Method of printing by spraying droplets of ink through computer-controlled nozzles. Also called jet printing.

Inorganic pigments: a class of pigments used in printing ink consisting of compounds of various metals; e.g., chrome yellow. Contains no carbon atoms.

Intaglio: an engraved or etched design which is below the surface as cells in an anilox roll or gravure cylinder.

Integral Proof: Color proof of separations shown on one piece of proofing paper, as compared to an overlay proof. Also called composition proof, laminate proof, plastic proof and single-sheet proof.

Intensity: color saturation.

Iridescent: Term used to indicate the property which is possessed by certain materials of exhibiting prismatic colors, also referred to as rainbow, peacock or interference effects. Sometimes mistaken with pearlescent.

Jelling: or gelling ; the thickening or bodying-up of an ink which cannot be reversed by stirring.

JPEG: Joint Photographic Electronic Group. A common standard for compressing image data.

K.B. value (Kauri-Butanol): A measurement of the solvent power of a hydrocarbon.

Ketones: A class of organic compounds; generally colorless, volatile liquids, as acetone, methyl ethyl ketone, etc. Often used in reducing type C and type T rotogravure inks.

Kick-out: see souring, precipitation.

Kiss impression: the lightest possible impression which will transfer the ink film from the transfer roll to the plate and from the plate onto the substrate.

Kraft linerboard: a paperboard made on a cylinder machine and used as the facing material in the production of corrugated and solid fibre shipping containers.

Kraft Paper: Strong paper used for wrapping and to make grocery bags and large envelopes.

Kromecote: a highly polished mirror-like finish on paper.

Lacquer: originally used to denote nitrocellulose type of fast drying inks and varnishes. Now more generally used as a term for any clear varnish with a plastic film-former base.

Laminate: to compose or bond two or more layers (e.g. films) of one or more types of materials. Usually through adhesives and compressed under some form of heat creating a laminate structure.

Laser-imprintable Ink: Ink that will not fade or blister as the paper on which it is printed is used in a laser printer.

Latent solvent: generally refers to less expensive solvents with little or no solvent power for a given resin and are used in combination with more powerful active solvents.

L.E.L.: the lower explosive limit of a solvent vapour. This is the lowest concentration of a combustible solvent vapour or gas in air which will produce a flash of fire if ignited. Mixtures below this concentration are too lean to burn.

Letterpress printing: The original printing process. The inked printing surface of a metal, rubber or plastic is above the non printing surface. The inking rollers touch only the raised printing surface which is then impressed onto the paper or board.

Letterset: see Offset letterpress

Lightfast: the ability of a color or film to withstand exposure to radiant energy (e.g., sunlight) without change from the original condition. A relative comparison.

Lines per inch: Measure of screen ruling expressing how many lines of halftone dots are contained in one inch. The higher the lines per inch (line screen) of a publication, the greater the sharpness of the images. Compare the photographs in a newspaper (generally around 85 lines per inch) with the photographs of a magazine (about 150 lines per inch). It is possible to run out an image with a high resolution (dpi) and a low line screen (lpi).

Lithography: printing from stone or plate, imaged with a medium which attracts oil-based ink. See also offset lithography.

Low density polyethylene (LDPE): standard polyethylene resin with a density above .910 but below .925

Magnetic ink: ink containing magnetic particles: used with MICR type to be read magnetically

Make-ready: Procedures required to prepare a press for printing. Includes all adjustments necessary to produce a satisfactory press sheet for the customer – from mounting and packing plates to ink control and image

Mass Tone: the color of an ink in bulk or when the film is thick enough to completely mask the substrate.

Match Color: In printing, the duplication of a specified color by using either multiple process colors or special flat colors. Match colors may be defined by supplied samples or by numbers from color matching systems.

Material Safety Data Sheets (MSDS): written or printed material aimed to inform the user or handler of a hazardous product. Includes the manufacturer's name, the chemical's synonyms, trade names, chemical family, hazardous ingredients, physical data, fire & explosion hazard data, health hazard data, reactivity data, spill or leak procedures, special protection information and special precautions.

Matte(ness): the "dullness" or "flatness" of a given stock or printed surface.

Mayer rod(s): a small diameter cylinder wound with a single layer of various diameter piano wire controlling the volume of coating material allowed to pass between the windings. Used to apply a definite thickness of ink or coating. The finer the wire, the less ink applied. Invented by Charles Mayer in 1905.

Melting point: the temperature in which a solid substance begins to liquefy under standard conditions.

Metamerism: condition when a light beam leaving two specimens are alike in color but differ in spectral composition. Observer metamerism is caused by differing color vision between viewers. Geometric metamerism is differing color when the angle of observation is changed.

Metallic inks: Inks in which the normal pigments are replaced by very fine metallic particles, typically, gold or silver in color.

Micron: a unit of measure. One millionth of a meter. 25 microns = .001"

Mid Web: web press having a width between 24” & 44”; see also Wide web & Narrow web

Middletone: the section of an ink drawdown that compares roughly to its full print tone.

Midtones: In a photograph or illustration, tones created by dots between 30 percent and 70 percent of coverage, as compared to highlights and shadows.

Mileage: the usage factor of an ink. Refers to the amount of ink used to cover a certain area of printed surface.

Mineral spirits: slow evaporating aliphatic naphtha. Hydrocarbon petroleum distillates having a boiling range of approximately 300-350°F (149-177°C)

Miscibility: the ability of a liquid or gas to dissolve uniformly into another liquid or gas.

Moire: Undesirable pattern resulting when halftones and screen tints are made with improperly aligned screens, or when a pattern in a photo, such as a plaid, interfaces with a halftone dot pattern.

Moisture Vapour Transmission Rate (MVTR): a relative description or rating of a substrate or printed substrate showing its ability to resist the passage of moisture vapour through packaging material.

Monochrome: consisting of a single color or hue.

Monomer: a chemical combination of molecules corresponding to the individual units of a polymer. It is capable of being incorporated (polymerized) into polymers.

Mottle: a speckled or indistinctly spotted appearance as in an ink lay. Attributable to various causes.

MVTR: see WVTR

Narrow web: in web printing (i.e. flexo), a press having a width of 24” or less ; see also Wide web & Narrow web

Neutral: the absence of acid or alkaline activity in a material. A pH of 7.

Nip: line of contact between two rolls.

Nitrocellulose (N/C): a film forming resin widely used in flexo and gravure. Nitrated cellulose (nitric acid ester of cellulose). Excellent heat resistant properties. Generally used as a binder in C-type rotogravure inks.

Non-flammable: (or non-inflammable) not readily combustible. The opposite of flammable.

Non-volatile: that portion of a material which does not evaporate at ordinary temperatures.

NPIRI: National Printing Ink Research Institute at Lehigh University, Bethlehem, Penna.

Off-line: Production operations conducted out-of-process rather than in-line (on-press), such as die-cutting or the application of special coatings via dedicated equipment.

Offset:
1. accidental transfer of printing inks or coatings from the printed surface to the back of another sheet. Also known as set-off. Usually caused by a wet or sticky ink film.
2. short for offset lithography

Offset letterpress: also called letterset - printing from a right-reading relief plate (or unusually, type) to blanket

Offset lithography: offset printing from a lithographic stone or plate - the plate prints first onto the blanket

Offset Spray: A dry spray of powdered starch at delivery end of press used to separate freshly printed sheets with a fine layer of particles, thus allowing the ink to dry and avoiding undesirable offsetting.

Opacity: the hiding quality of an ink film; non-transparency.

Organic: refers to the compounds in the field of chemistry containing carbon.

Overlay Proof: Color proof consisting of polyester sheets laid on top of each other with their image in register, as compared to integral proof. Each sheet represents the image to be printed in one color. Also called celluloid proof and layered proof.

Overprint: the process of printing one impression over another.

Pantone® Matching System: Often referred to as PMS, the Pantone® systems are the most popular color matching systems in the printing industry. A true PMS color is defined by a mixture of inks that will provide a specific color (e.g. PMS* 185 is a very common bright red color). Pantone also provides a matching system that allows process printers (using only CMYK inks) to closely, but not exactly, match any of the PMS standard ink colors. Pantone, PMS and the Pantone Matching System are trademarks of Pantone, Inc. Go to GF Enterprises’ Pantone Products page to browse the Pantone products offered.

Paperboard: Any paper with a thickness (caliper) of 12 points (.3mm) or more.

Paper Grain: The alignment of fibres along the direction of flow in papermaking. In grain-long paper, fibres run parallel to the sheet’s length, while grain-short follows the width. Generally, registration is easier to control, folds are cleaner, and binding stronger when running with the grain.

Pastel: a tint or masstone to which white has been added.

Pearlescent: Term used to indicate the property which is possessed by certain materials of exhibiting pearl or oyster satin like effects. May also refer to the pigment producing this effect. Sometimes mistaken with iridescent.

Penetration: the ability of a liquid (ink, varnish, or solvent) to be absorbed into the paper or other printed media.

pH: the logarithm to the base of the reciprocal of the concentration of hydrogen ions in an aqueous solution. The degree of acidity or alkalinity measured on a scale of 0 to 14 - 7 being neutral. from 0 to 7 is acid; from 7 to 14 is alkaline. The scale being logarithmic, a one point difference represents a tenfold change.

item

pH

lemon juice

2

vinegar

3

skin

4-6.5

coffee

5

water (pure)

7

blood

8

baking soda

9

Rolaids, Tums

11

bleach

13

Phenolic: a generic name for phenol-formaldehyde plastic.

Phosphorescent: a luminescence that has been caused by the phosphorescent pigment's absorption of radiation and continues for a noticeable length of time after the radiations have ceased.

Photopolymers: generic name for a mixture of materials that can change physical properties on exposure to ultraviolet or visible light. They are widely used as off press proofing materials and printing plates.

Pica: A unit of measure in the printing industry. A pica is approx. 0.166 in. There are 12 points to a pica.

Picking: the lifting of any portion of a surface during the printing impression.

Pigment: substances which impart color to an ink; they are finely divided and suspended in the ink mixture, usually insoluble in such a mixture.

Piling: the build-up of ink on rollers, plates or blankets.

Pinholing: refers to the failure of a printed ink to form a continuous film. This condition will become visible by the appearance of small "holes" in the solid print area.

Plasticizers: materials, some liquid and some solid, which are added to an ink formulation to soften, toughen, increase adhesion, impart flexibility, or otherwise modify the ink film; flexibilizers.

Plate: Piece of paper, metal, plastic, or rubber carrying an image to be reproduced using a printing press. Produced photographically using film negatives to control the photographic exposure of the plate. Exposed areas of the plate hold ink on press, thereby reverting the negative image back into a positive.

PMS: Obsolete reference to Pantone Matching System. The correct trade name of the colors in the Pantone Matching System is Pantone colors, not PMS Colors.

Point: (1) Regarding paper, a unit of thickness equating 1/1000 inch. (2) Regarding type, a unit of measure equalling 1/12 pica and .013875 inch (.351mm).

Polar solvents: solvents with oxygen in their molecule; e.g., water, alcohols, esters and ketones.

Polyamide(s): polymers containing amide groups; for example: Nylon, Versamid resins, etc.

Polyethylene (PE): a synthetic resin of high molecular weight resulting from the polymerization of ethylene gas under pressure.

Polymer: a compound formed by the linking of simple and identical molecules having functional groups that permit their combination to proceed to higher molecular weights under suitable conditions.

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.

Polypropylene (PP): a synthetic resin of high molecular weight resulting from the polymerization of propylene gas.

Polystyrenes: a class of low cost, water white, hard resins. While more commonly used in the plastics industry, they have found increased acceptance as paper and paperboard gravure topcoats because of their price, gloss, and other desirable properties.

Porosity: the quality or state of being permeable.

Precipitate: an insoluble substance that forms in a solution.

Press ready: term used by ink makers to describe inks which can be used directly by printers without additional modification.

Press viscosity (or printing viscosity): Viscosity which is recommended for printing.

Primary colors: those from which all other colors mat be derived.

Process Colors or Process Printing: see four color process.

Proprietary Solvent Alcohol: a completely denatured ethyl alcohol which is mixed to a set of government specifications and sold by the vendor under his own trade name.

Ream: the unit of quantitative measure used in the marketing of paper consisting of a specified number of sheets of a specified size. 500 sheets of paper.

Reducers: materials used to reduce the body, viscosity or strength of an ink; may be extender white, varnish, or solvent blend.

Register: in printing, the fitting of two or more images on top of each other in exact alignment.

Relative Humidity: the percentage of water vapour in the air compared to the total amount possible at the same temperature.

Resins: complex organic substances which in solvent solution form the flexographic varnish. Upon drying of the ink, the resins become the binder, or film-forming materials in the printed ink film.

Retarders or retarding solvents: higher boiling point solvents used to reduce the drying speed of inks and coatings.

RGB: Abbreviation for red, green, blue, the additive color primaries. Red, Green, and Blue are used in television and computer monitors to create all colors.

Rheology: see viscosity.

RIP: Abbreviation for Raster Image Processor: a device or computer program that receives a description of the content of a page and converts it into information that can be output on paper, film, plates, slides or any other medium.

Rub: the characteristic of an ink or coating referring to its resistance to abrasion.

Rub resistance: see abrasion resistance.

Saturation: the extreme degree of concentration beyond which a substance can no longer be absorbed into another medium. (e.g., the point in which salt can no longer be dissolved in water.)

SBS: Premium quality virgin fibre based Solid Bleached Sulphate board of medium density, generally very high whiteness and cleanliness of surfaces and cross-section.

Screen Angles: Angles at which screens intersect with the horizontal line of the press sheet. The common screen angles for separations are black 45 degree, magenta 75 degree, yellow 90 degree and cyan 105 degree.

Screen Printing: Formerly called silk screen printing. Rather than print from a plate or cylinder, a stencil is prepared by hand or photographically on a screen or mesh. Ink is then forced through the screen and onto the substrate. Halftones can be reproduced, very thick ink films carried, and printing is possible on difficult surfaces such as the inside of bottles.

Scuff: (1) to rub or abrade, (2) a surface abrasion.

Scuffing: Undesirable print abrasions caused by surface wear or rough handling. Particularly problematic in packaging, scuffing may be minimized with scuff-proof inks, varnishes, and other coatings.

Scuff resistance: see abrasion resistance.

Scum: A film or ink printing in the non-image areas of an offset-litho plate.

Scumming: In rotogravure printing, a deposit of ink in the non-printing surface of a cylinder, very light in character, almost a haze.

Second Pass / Dry Pass: The extra passage of a sheet through the press for additional color impressions or coating applications.

Set off: accidental transfer of image on one sheet to the back of the next

Sheet fed: A press accommodating individual sheets rather than the paper rolls required of higher-volume web presses. Sheetfed presses facilitate make-ready and minimize paper spoilage, and the feeder mechanism accepts a wider range of paper stock.

Shelf-life: the resistance to deterioration by oxygen and ozone in the air, by heat and light, or by internal chemical action.

Signature: Printed sheet folded at least once, possibly many times, to become part of a book, magazine, or other publication. Printed signatures look like the pages are out of order. Only after folding do the pages fall in numerical order.

Skips: In rotogravure printing, refers to dots in a screen form that have not been printed. Usually due to a rough printing surface, lack of impression or both.

Slip: general term given to an ink or coating denoting the degree of slipperiness or slide.

Slip compound: an additive for ink that imparts lubricating qualities to the dried ink film.

Slur: A printing defect caused by movement of the sheet, blanket, or plate on press, resulting in elongated, blurred (or slurred) halftone dots and fine line distortion.

Softening point: temperature at which plastic material will start to deform with no externally applied load.

Solids Content: the percentage of non-volatile matter of which a compound or mixture is composed such as ink. and based on weight of the entire mixture. e.g., pigment, extender, binder, plasticizer, dry wax, etc.

Solution: a homogenous mixture of two (or more) substances in which a solid, liquid, or gas forms a single phase (to be dissolved) with another liquid (or sometimes a gas or solid), and which has the same physical and chemical properties throughout at any given concentration up to its saturation point.

Solvent: a liquid, usually organic, which is used to dissolve given solid materials such as resins.

Solvent release: 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 foreign materials. Also referred to as "kick-out".

Specific Gravity: a comparison of the weight of a given volume of a material with the weight of an equal volume of water. Stated numerically, water has a specific gravity stated as 1. An ink may have a specific gravity stated as 1.34 - that is, a given volume weighs 1.34 times as much as the same volume of water.

Spectrophotometer: a photoelectric device used to measure the relative intensity of wavelengths of radiation that is transmitted or reflected from a sample. Modern spectrophotometers are accompanied by advanced software that allow for detailed color comparison and even color matching.

Spectrum: the series of color bands diffracted and arranged in the order of their respective wavelengths by passage of white light through a diffracting medium and shading continuously from red( the longest wave possible) to violet (the shortest wave possible).

Spot color: One ink color applied to portions of a sheet. Differs from four-color process color in that a spot color is a specifically colored ink that is mixed up to match a pre-chosen hue. Works similarly to the way paint is mixed at a hardware store to match a specific color. Spot colors tend to be brighter and more vibrant than their process color counterparts. Many spot colors are unproduceable in process color due to spot color's immense color gamut. Fluorescents and metallic inks can only be produced with spot color. If you have a spot color logo and move to process color printing, you should accept and expect some color shift in the final printed piece. Depending on the color, the shift can be dramatic.

Stabilizing Varnish: a varnish high in amines used press-side to stabilize the pH of an ink during a run to compensate for lost amines due to heat or evaporation.

Stickyback: double faced adhesive coated material used for mounting plates.

Stochastic Screening: a digital screening process that converts images into very small dots (14 - 40 microns) of equal size and variable spacing. Second order screen images have variable size dots and variable spacing. Also called Frequency Modulated (FM) screening

Stock: see substrate.

Strength: usually refers to the intensity of a color.

Styrene: styrene monomer is produced by the dehydration of Ethyl benzene and utilized as the raw material of synthetic resin. Colorless liquid with a sweet, aromatic odour at low concentrations; sharp, penetrating, disagreeable odour at higher levels. SYNONYM(s): Phenylethylene; Vinylbenzene; Cinnamene; Styrene monomer CAS: 100-42-5 / MW: 104 / BP: 145-146°C / VP: >1 atm / MP: -30.6°C

Stripping: The assemblage of film for platemaking. Stripping involves correcting flaws in film, assembling pieces of film into forms, and ensuring that the film and forms register correctly.

Sublimation: the transformation of a solid directly into a gas without passing through the liquid state. In the process of transferring a colored design printed on a paper carrier web to a textile, the sublimation of the dye used permits the vapour to penetrate and color the synthetic fibre.

Substrate: refers to any material on which printing is done. May be board, foil, paper film, etc.

SWOP: Abbreviation for specifications for web offset publications, specifications recommended for web printing of publications.

Substrate: generally refers to the matter or base in which the printed film will be applied upon. Also referred to as stock.

Surface Tension: a force existing at various solid, liquid and gas interfaces which tend to bring the contained volume into a form having the least superficial (lying on , not penetrating below) area.

Tensile strength: the maximum load in tension that a material can withstand without failure.

Text Stock: A paper stock used for sales sheets, data sheets, and other printing where the stiffness of card stock is not required. Text stock is described by pound weights. Standard US text pound (#) weight is determined by the weight of 500, 25" x 38" sheets. For example; 500 sheets of 80 lb. text stock, cut 25" x 38" would weigh 80 lbs. (Note that card stock is measured differently than text and assumes 500 sheets of 20" x 26" to determine pound weight).

Thermoplastic: a resinous material that becomes soft when heated.

Thinners: liquids, solvents and/or diluents, added to ink for diluting or thinning purposes.

Thixotropic: false body; that property of a liquid which prevents free and ready flow until well agitated. Can be a useful quality in keeping pigments suspended during storage; usually an undesirable but unavoidable property.

Tinctorial: refers to relative color strength of ink. A strong ink has high tinctorial value.

Tint: a color of very low strength or intensity, usually made by adding a small amount of colored ink or toner to a large amount of extender or opaque white. Tints are often characterized by difficult color control and potential color burnout. Pantone® tint matches are four digit numbers beginning with 9.

Toxicity: refers to property of being toxic or poisonous; may be used in referring to injurious effects of a solvent, ink or varnish.

Transparency: inks which do not possess hiding power thus allowing light to pass through.

Trapping: refers to the condition of printing an ink over another ink.

Tristimulus: color readings based on the primary colors, yellow, magenta & cyan.

Two-pot system (or two part system): inks and coatings in which two reactive components are mixed together at press time.

Ultra Violet (U.V.): situated beyond the visible spectrum. Used of radiation having a shorter wavelength of that of visible light and longer than those of X-rays. Relating to producing ultra-violet radiation which serves as a catalyst to the curing of U.V. based inks and coatings. In the 300-400 mm range. (or nm)

Uncoated Paper: Also called offset paper and often referred to as copier paper, this stock has no coating and allows ink absorption during the printing process. As the ink is absorbed by the various paper fibres, it diffuses the image and lessens contrast between colors. Uncoated stock is less expensive than coated stocks, and is often used to reduce costs on jobs where quality is not the primary concern.

Undertone: the appearance of a thin film of ink when looking through it. This tone is developed when the ink is tinted with white or extender.

Unsized stock: absorbent paper to which no size has been added in the pulp or on the paper machine in its manufacture.

U.V.: Ultra violet light radiation from a source as a high intensity mercury vapour tube emitting light in the 314-400 millimicron (or nanometre) range.

Varnish:
1. the vehicle or "carrier" component of an ink. Flexographic varnishes are usually composed of resins and/or film-formers dissolved in a solvent or a blend of solvents. Plasticizers, compounds and waxes may also be a part of the varnish.
2. A clear-coat liquid sealer that overprints ink and paper to protect against scratches and scuffing, increase longevity, and enhance image appearance and impact. Can be gloss or dull.

Vehicle: name often applied to the varnish portion of a printing ink.

Viscometer (or viscosimeter): instrument used to measure the viscosity of an ink, varnish, or other solution. Some examples; Zahn cup, Ford cup, Brookfield viscometer, etc.

Viscosity: quality relating to the internal friction of an ink -- such friction affecting the ink's ability to flow.

V.O.C.: volatile organic compound.

Volatile: quickly evaporating; readily vaporizable.

Wash Up: The process of cleaning ink and press components for changing colors or preparing for a new print job.

Web: the paper, foil, film or other flexible material, from a roll, as it moves through the machine in the process of being formed or in the process of being converted, printed, etc.

Wetting: (1) refers to the action of surrounding the minute particles of pigment (or resin) with the "wet" solvent, during the ink making procedure. Pigments which will "wet out" easily will, in general, grind more easily, form better ink bodies, and have a finer dispersion. (2) also used in reference to the further thinning of an ink or varnish, by the addition of more solvent and/or diluents. (3) the ability of an ink to spread evenly over the surface on which it is printed.

Wetting Agents: chemical compounds which may be added to an ink to make for more "wet out" of the pigment. Used as an aid in the dispersion process. Used to improve the "spreading" or "laying" properties of an ink film on a substrate.

Wide Web: in web-printing (i.e. flexo), a press having a width greater than 44”; see also Narrow Web

Work-and-tumble: In sheet-fed printing, a press imposition method using the same plate for printing both sides of a press sheet, where the sheet is tumbled end-to-end for second pass printing on the back. Because the gripper edge is changed and press adjustments made, this method is rarely used when precise register is critical.

Work-and-turn: In sheet-fed printing, a press imposition method utilizing the same plate for printing both sides of a press sheet, where the back-up, or second side, is printed by turning the sheet over – from left to right. This method provides better register than work-and-tumble by maintaining the same gripper.

WVTR: Water Vapour Transmission Rate: The rate at which the moisture vapour contained in a carrier gas can permeate through film and into a dry atmosphere on the other side. Generally recorded in units of gm/100 in²/24hr (gm/m²/24hr). Also known as MVTR.

Yield: number of square inches of film per pound of product per mil.

Zahn Cup: a device for measuring viscosity. Also known as an efflux cup.

4/0, 4/1, 4/4: with four colors (full color) on one side and no printing, one color printing and four color printing on the back, respectively. Pronounced four over zero, four over one, and four over four.

5,000K Lighting: Light measuring 5,000 degrees Kelvin (the color temperature of bright daylight). A component of industry-standard viewing conditions for inspecting transparencies, comps, proofs, and press sheets.

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