Follow Us: Twitter LinkedIn Facebook


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.

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

American Wire Gauge (AWG)

A wire diameter specification where the smaller the number designator, the larger the wire diameter.

amine resin

Synthetic resin derived from the reaction of urea thiourea, melamine, or allied compounds with aldehydes, particularly formaldehyde.

ammonium bichromate (ammonium dichromate)

A compound or salt used for rendering colloids or emulsions active to actinic light such as in photostencils.

ammonium fixer

Photography, a fixing bath containing NH4+ (univalent ion of ammonia) that is used for removing silver halides from photosensitive emulsions.

ampere (A, amp)

A standard unit of current produced by one coulomb of charge passing a point in one second.


Capable of acting either as an acid or base.

ampule (ampoule)

A small hermetically sealed glass container that is designed to be filled and then sealed by fusion of the glass neck.

amyl acetate

Used in some lacquer formulations because of low evaporation rate.

analogous color

Colors that appear next to the primaries on the color wheel; different colors related by having the same base for example blues and purples are analogous.

Analysis of Variance (ANOVA)

The systematic method of statistically evaluating experimental results in order to separate the sources of variation.

anamorphic distortion

Changing the perceived shape of an object in an image based on mathematically defined criteria.

anchor coat (primer) (tie coat)

A coating applied to the face material prior to the application of a pressure sensitive adhesive, to improve bonding (or anchoring) of printed inks.


Specific adhesion of an adhesive agent to a face material or anchor coat.

angle of attack

The angle formed by the face of the moving squeegee blade and the plane of the screen, under pressure. (Due to the flexibility of the blade, this angle generally differs from the squeegee angle, which is measured without movement or pressure).

angle of view

That portion of a subject which is seen by the camera lens, as determined by the focal length of the lens.


Used to express the length of light waves; a standard measure of a lightwave; a unit of length equal to one hundred millionth (10-8) of a centimeter. (The visible spectrum extends from red light, 7,000 angstrom units, to violet light, which is about 4,000 angstrom units).

aniline dye

Synthetic dyestuff made from coal tar or its derivatives.

aniline point

The temperature at which a volume of a hydrocarbon will dissolve an equal volume of aniline oil. (The aniline point is regarded as the temperature at which the mixture becomes homogeneous and is useful in evaluating solvent power).


To make or produce, so as to create the illusion of motion.


To heat a material to a predetermined temperature and slowly cooling it to relieve stress and make it less brittle, also refer to temper.


An electrochemical oxidation of aluminum to form a porous aluminum oxide surface, which can be colored and is nonconductive, non-corrosive, and resistant to abrasion.


The process of adding a protective oxide film to metal by an electrolytic process.


Acronym for Analysis of Variance.


Acronym for American National Standards Institute; formerly the American Standard Association.


The removal or softening of image rough edges (jaggies) by averaging or blending of surrounding colors.

anti-skinning agent

Chemical substances that retards skin formation on the surface of an oxidizable ink; sometimes referred to as antioxidants.

anti-static agent

Medium which when added to the molding material or applied on the surface of the molded object, make it less conducting.

anti-static solution

Any liquid sprayed or otherwise coated onto a surface that tends to prevent or reduce the build up of static electricity.

antiforming agent

Ink additive that breaks foaming bubbles that may occur during printing.


A coating or backing put on a film or screen mesh to prevent blurring and/or spreading of light by reflection from the film base or threads. (In screen mesh, antihalation is achieved by dyeing the fabric various shades of yellow, orange, or red).


A chemical substance that selectively reacts with oxygen to inhibit or prevent oxidation.

antique finish

A natural or cream color, relatively rough finish on paper stock resulting from the use of long nap felts on the wet presses that are run with light pressure to give bulk, and with little calendaring pressure.

anvil cut label

Pressure sensitive label that have been die cut through components of the label stock.


(1) The open area in screen printing mesh between the threads; (2) Opening in a camera lens through which light rays pass from subject to film plane to form an image.

apochromatic lens

A process lens that has been corrected for both chromatic and spherical aberrations.