Glossary Of Terms

The SGIA Glossary of Terms serves as an excellent industry terminology resource. It is the language by which we all communicate, without it universal understanding would be impossible. Language and our ideas about how it is interpreted change rapidly. SGIA is aware of this and continues its effort to keep our constituents well informed about changes to the increasingly complex industry terminology. The definitions are for general reference only. Usage may vary between companies, individuals, or national and country customs. The information presented is as accurate as the authors and editors can ascertain and SGIA assumes no responsibility for the use of information presented herein.


  • Exhaust system
    A system where a duct or flue, and/or blower system is used to remove air or gases from a dryer or lehr.
  • Exothermic
    The property of giving off or releasing heat; heat generated by a chemical reaction.
  • Expanding corner frame
    Screen frame that has hollow metal section fitted with elbow in the corner that are designed to expand to tension the mesh.
  • Expansion
    An overall increase in the dimensions of a substrate.
  • Expansion factor
    Correction factor for the change in density between two pressure measurement areas in a constricted flow.
  • Explode
    To burst suddenly and violently.
  • Explosive
    A substance that can explode.
  • Exposure
    (1) A predetermined length of time that a given photosensitive emulsion or film is affected by a controlled intensity of actinic illumination, product of intensity and time; (2) Occurs when an employee is subjected to hazardous chemical; (3) The length of time that a material is exposed to environmental influences; (4) An individual prospective consumer’s sensual contact with a POP display or other advertising media.
  • Exposure area
    The area of a light sensitive material that is subjected to change by action of actinic light rays.
  • Exposure calculator (graphic)
    A circular slide rule or system of concentric dials for computing proper camera exposure by matching lens aperture, shutter speed, light intensity, and camera distance on the several dials.
  • Exposure calculator (screen)
    A inexpensive device used for determining the correct exposure time for photostencil films and emulsions.
  • Exposure index
    A number assigned to a photographic material to relate its speed to other photographic materials.
  • Exposure latitude
    (1) The range of camera exposures, from underexposure to overexposure that will permit acceptable reproduction; (2) The range of exposure for an emulsion coated screen that will permit acceptable reproduction with no loss of detail and still be fully cured.
  • Exposure meter
    An instrument that measures the intensity of light that is reflected from a subject or light that reaches the lens, indicating practical exposure recommendations and f-stop.
  • Exposure test
    A test made by exposing to actinic light sensitized films or coatings for a series of equal time intervals at a given distance from light sources, in order to establish standard time of exposure and standard distance of light from sensitized surface.
  • Exposure time
    The relative amount of time in seconds or minutes during which a photosensitive material is acted upon by light.
  • Exposure unit
    The light source or system used in exposing photostencil materials.
  • Extender base (extender)
    A non-pigmented transparent or white binder used to increase ink volume without reducing viscosity, which reduces the ink strength without affecting its hue.
  • Extender pigment
    A pigment added to an ink to reinforce the color, but typically having little effect on opacity.
  • Extensibility tester
    Instrument used to measure the elongation of a material by applying stress on the original cross-sectional area of the specimen.
  • Exterior durability
    A measure of the length of time a print will withstand outdoor exposure without appreciable loss of quantity.
  • Extra spacious pocket
    A display pocket with greater width, depth, or length, or any combination above the usual size.
  • Extrusion
    To shape by forcing through a die.
  • Exudation
    The migration of solid materials to the surface of a film.
  • Eyelet
    A rimmed metal or plastic grommet inserted into the holes of a banner or display for reinforcement.