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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.

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

apparent dot area

Percentage of dot coverage in a specific area, as measured using a densitometer and calculated using the Murray-Davies equation.

apparent dot gain

Difference between the apparent dot area of the film, as measured by a transmission densitometer, and the apparent dot area of the proof or printed sheet, as measured with a reflection densitometer. (Indicates how much the dots of ink have spread in relation to the original film dot area).

apparent viscosity

A characteristic of multi-component liquids that have a variable ratio of shreds stress over shear rate (variable viscosity depending on conditions).


Manifestation of the nature of objects and materials through visual attributes such as size, shape, color, texture, gloss, transparency, and opacity.


(1) An adhesive-coated film emblem, or decal affixed to a designated substrate; (2) An ink or color screen printed directly onto a substrate; (3) Often used as a general term to designate a particular screen printed product; (4) The highest level of software that a user sees; also a generic term for software.

application printing (textile)

The placement of coloring agents directly onto the fabric substrate.

application temperature

The minimum temperature at which a pressure sensitive material can be applied to a surface.


An instrument or equipment for applying something such as a device that automatically feeds and applies labels to the product.

applied color decorating

Decorating by applying color directly onto the substrate, as opposed to using transfer or decal techniques.


Extension area of lehr for handling of ware, also be applied to extensions of conveyor dryer for stock handling.

aqueous dispersion

Pigments dispersed in a water soluble binding medium that changes to a water insoluble form when the printed cloth is steamed or heat cured.

arc resistance

The resistance to current flow across the surface of the material measured as the time required for an arc to establish a conductive path in a substance.


Term loosely used to refer to material that can be used without side effects in the conservation or care of important artifacts. Pertaining to the production of new items designed to have very good aging qualities. e.g. non-fading inks, acid free paper, etc.

archival ink

Ink used in fine art digital printing that has been optimized for permanence.


Retention of images, often on CD-ROM, for a specified period. Information necessary to reproduce the print is also archived, including ink, tables, sizes, and media used.


A spark discharge of electric current crossing a gap between two electrodes.


A colorless, odorless inert gas.

aromatic solvent

Organic liquid derived from products of petroleum origin having a cyclic or ring hydrocarbon structure and KB (Kauri Butanol) value over 40 such as toluene or xylene.

art knife

A tool with an usually small, keen blade used for very light cutting of sheet material such as frisket paper, masking film, tracing sheet, and other such materials.

art paper

A coated paper often having a high finish used in printing halftones.

art print

Printing of original or reproductions of artwork with any number of methods. Iris/Giclee/Inkjet, lithography, offset lithography, serigraphy being the major sources for Art Print production.

art reproduction

To make a reasonable facsimile of an art object. Could be reproduced in any of a number of methods; painted, inkjet, serigraph, offset lithography, sculpted, cast etc.

art type

Type faces, designs, and individual characters screen printed onto gummed acetate sheets. (The type or designs are cut from the acetate sheet and made to adhere to the copy by merely pressing on or rubbing gently), also refer to alphabet sheets.

art work

The original copy intended for reproduction, also refer to rough art and camera ready art.


Unwanted visual anomalies or defects generated by an input or output device, or by a software operation, that degrade image quality. See also aliasing, moiré pattern.

artificial daylight

Man-made light source that closely reproduces the color and spectral distribution of natural daylight.

artificial fiber

A classification of manufactured fibers made from natural sources such as wood or other plant material.

artificial fiber

A classification of manufactured fibers made from natural sources such as wood or other plant material.

artist’s proof

Prints or serigraphs from an edition that are owned by the artist and generally are not offered for sale. (They are of the same quality as numbered prints in the edition).

ASA rating

The American Standards Association (US) scale by which the relative sensitivity of photographic films is identified, largely replaced by DIN and ISO rating scales.


The portion of a lower-case character that extends above the main body such as b, d, or h.

aspect ratio

(1) Ratio of length to diameter of a fiber; (2) Relationship of an image horizontal length and vertical height, designated with horizontal number first such as 3:2.


Acronym for American Society of Quality (USA), formally American Society for Quality Control (ASQC).


A reflective defect of a lens that prevents focusing of a sharply defined image and from bringing horizontal and vertical lines to a sharp focus at the same time on a flat surface.