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Specialty Graphic Imaging Association
SGIA Glossary

Definition Glossary

Sixth Edition

Language and our ideas about how it is interpreted change rapidly. The Specialty Graphic Imaging Association (SGIA) is aware of this and continues its effort to keep our constituents well informed about changes to the increasingly complex industry terminology. This publication represents the most recent changes.

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acid proof (acid resistant)

Quality of a material that prevents or lessens the effect of contact or immersion in acid.

acid stop bath

A photographic solution, generally acetic acid, used for stopping the action of the developer on a photographic positive, negative, film or paper.

acid wash

Chemical mechanical process where dye is taken out of a garment, producing a splotchy look that can range from large to a very fine; also referred to as rough cutting a garment.


Acceptable acronym for applied color labeling.

ACL lug

A small protrusion or depressed cavity manufactured in containers to act as a guide in positioning decorations; also refer to ramp.


Computer command, typically under "File" menu, that allows the start of scanning software directly from the application. Acquire is only available if the software is TWAIN-compliant.

across grain

A direction that is 90 degrees to the machine grain imposed in the making of paper from fiber; also refer to cross direction.


An ester or salt coming from acrylic acid; a type of monomer used in UV ink and coating formulations that contains the chemical group CH2=CHCO2H.

acrylic based adhesive

A pressure sensitive adhesive based on acrylic polymers.

acrylic emulsion

A water based latex made with acrylic polymers used for coatings and/or impregnating.

acrylic ink

Ink containing acrylic polymers used for screen printing on some plastics and other substrates, especially where outdoor exposure is involved.

acrylonitrile-butadiene-styrene (ABS)

A thermoplastic derived from acrylonitrile, butadiene, and styrene, the strongest of the styrene copolymers and the most widely used.

actinic light

A ray of light that is composed of short wavelengths as found in the ultraviolet and violet areas of the spectrum; capable of changing the properties of photosensitive materials on exposure to the light source.


To accelerate a reaction or increase chemical activity.

activated carbon

A powdered or granular carbon that is highly absorbent, used to remove organic vapors and odors.

activated sludge treatment

A water effluent waste treatment employing forced air to accelerate biodegradation process.


(1) A chemical used to accelerate a reaction or increase chemical activity in another material; (2) In photography, a high pH solution that allows diffusion of the developer into the film emulsion for development of the image.

active component (active devise)

A part or element in an electronic device that controls current or voltage to produce gain, impede or resist flow, or provide switching action in a printed circuit.

active substrate

A substrate or base for an integrated circuit component where parts of the substrate display voltage or current control to accomplish gain, impedance, or switching.


In thermodynamics, the active concentration of a free ion in solution.

actuation force

(1) The amount of pressure necessary to close a membrane switch, measured in grams; (2) The force required to collapse the walls of a rubber keypad, metal, or polyester dome.


The acute details of shape or sharpness of the edge of a printed line or dot.


A toxic effect that results from a short term exposure to a very high concentration of a toxic substance.

acute effect

The adverse effects that normally are evident immediately, or shortly after exposure to a hazardous material, generally no longer than 14 days.

adaptive compression

A type of compression software commonly used to back up files. The method of compression will change with the type of file, and is not recommended for photographic images because it may destroy original data.


A substance added in small amounts to another to improve desirable qualities or suppress undesirable properties, or otherwise changes the composition to a predetermined state.

additive color matching

Process that can specify colors in terms of the three numbers representing the amounts of the three primary lights added together to make a match. (The amounts of the three primaries, expressed in numerical form for each primary and describing the new color, are known as the tri-stimulus values of that color).

additive lamps

A medium pressure mercury vapor UV lamp (arc or microwave) that has small amount of metal halide added to the mercury. (These materials will emit their characteristic wavelengths in addition to the mercury emissions).

additive primary colors

Red, green, and light blue; when all additive primaries are combined at 100% intensity, white light is produced; combining at varying intensities produces a gamut of different colors.

addressable resolution

The highest resolution of a printer, scanner, etc. in working with an image, also refer to optical resolution and interpolation.


Any item that is attached to another item or surface by an adhesive.

adhering liquid

A solvent used for attaching lacquer-filled knife-cut stencil film to the screen mesh, usually a blend of lacquer-type solvents.


The molecular force of attraction between unlike materials; being united or attached, by a mechanical, chemically, or reactive bond between surfaces causing them to stick together; (adhesion to a smooth surface may rely on polar adhesion).

adhesion buildup

An increase in the peel adhesion value of pressure sensitive tape after it has been allowed to dwell on the applied surface.

adhesion shear

A measure of the time required to slide a standard area (as of a decal) from a standard flat surface in a direction parallel to the surface.

adhesion test

Any of a variety of test methods used to determine adequate bonding of ink or coating to a substrate.