Glossary Of Terms

The PRINTING United Alliance 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. PRINTING United Alliance 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 PRINTING United Alliance assumes no responsibility for the use of information presented herein.


  • CIE standard observer
    A hypothetical observer having the tristimulus color mixture data recommended in 1931 by the CIE to a 2° viewing angle. (If not specified the 2° standard observer should be used. If field of view is larger than 4° the 10° standard observer adopted in 1964 should be used).
  • CIE tristimulas values
    The amount of the three reference or matching stimuli required to give a match with the color stimulus considered in a given trichromatic system.
  • Circle cutter
    A compass fitted with a sharp blade for cutting perfect circles.
  • Circuit
    (1) Electronic path between two or more points; (2) Number of conductors, interconnected for the purpose of carrying an electric current.
  • Circuit pattern
    The configuration of components, their interconnecting printed wiring, as printed to form an electronic circuit, or as designated by an electronics engineer.
  • Circular screen
    A circular halftone screen which may be rotated to allow multiple screen angle selection without having to reposition copy.
  • Cissing
    A defect where a wet ink or varnish recedes from small areas of the surface leaving either no coating or an attenuated one.
  • Citric acid
    An organic acid used in testing the acid resistance of ceramic colors.
  • Clamshell press
    (1) A heat transfer machine/die-cutting machine with two platens, one directly over the over and hinged together on one side to open and close like a clam’s shell; (2) A flatbed screen printing press designed with the screen carriage hinged to the printing table at one end.
  • Clarifier
    (1) An additive that increases the transparency of an ink or other material; (2) A settling tank where solids are mechanically removed from process waste water.
  • Clarity
    The characteristic of a transparent material such that distinct images may be observed through it.
  • Clay coated board
    Display board with excellent print acceptance and brilliant white color manufactured in a variety of thickness, coated on one or both sides with an earthy material to improve the quality of the printing surface.
  • Cleanroom
    An enclosed area where airborne particles, temperature, relative humidity and pressure are controlled to specified requirements.
  • Clear coat
    Transparent protective coating applied over a screen printed image to ensure maximum durability.
  • Clear frit
    A frit that remains essentially transparent when processed into a porcelain enamel.
  • Clear glaze
    A transparent colorless ceramic glaze.
  • Clear ink coat
    A colorless printable compound of varnish or transparent material.
  • Clear vinyl
    Vinyl plastic formulated so that the resulting sheet or film is transparent.
  • Clearance
    The smallest distance separating conductive parts at a specified setting on a membrane switch.
  • Clearing
    A process of removing fog from the film negative or positive during development.
  • Clearing agent
    A chemical that neutralizes hypo in film or paper processing, thereby reducing washing time and producing a more stable image.
  • Cleat
    A strip of wood or metal used to strengthen a sign, display, or other construction.
  • Cliche
    A photoengraved pad printing plate made of steel or plastic.
  • Clip
    A display part used for attaching small items to the back of a display.
  • Clip art
    Previously developed designs and graphics used in composing artwork, copyright free and/or purchased for a fee.