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.


  • Peripheral
    Any of a number of hardware devices that extend or enhance the performance of the computer and are not part of the CPU, though some are mounted inside the case of the computer.
  • Permanence
    The quality of a substance or bond to resist deterioration.
  • Permanent adhesive
    An adhesive with relatively high ultimate adhesion properties.
  • Permanent ink
    Ink that resists fading or change of color when exposed to light and air.
  • Permanent paper
    A paper that resists the effects of aging, usually acid-free, used for archival or artistic (serigraph) prints.
  • Permanent violet
    A light resistant, tungstated or molybdated methyl violet pigment used in screen printing inks; carbazole violet.
  • Permissible exposure limit (PEL)
    Concentration in air that has been declared safe to breathe by the US Occupational Safety and Health Administration (OSHA).
  • Permittivity
    The ratio of electric flux density produced by an electric field in a medium to that produced in a vacuum by the same field; also refer to dielectric constant.
  • Persian orange
    A clean, brilliant, transparent flaked orange ink pigment.
  • PET
    Acceptable acronym for polyeylene terephthalate.
  • Peta (P)
    A prefix utilized in the metric system of measurement that denotes 10 to the fifteenth power (1015) or 1 000 000 000 000 000.0.
  • PETG
    Acceptable acronym for polyeylene terephthalate cyclohexanedimethanol.
  • Petroleum naphtha
    Weakest hydrocarbon solvent with KB value of 20.
  • PFP fabric
    "Prepared to print" fabric that has been pre-scoured and heat-set to make it suitable for printing.
  • PH (pH value)
    A measure of the acidity or alkalinity of a solution on a scale of 1 to 14. (A substance with a pH value of 7 is neutral; acids have pH values below 7; alkalis have pH values above 7.).
  • Phase
    A time-based relationship between a periodic function and a reference. (In electricity, it is expressed in angular degrees to describe the voltage or current relationship of two alternating waveforms.)
  • Phase change printer
    An ink jet printer where a solid ink is heated and liquefied for disbursement.
  • Phenolic (PF)
    An opaque thermoset plastic produced by the condensation of an aromatic alcohol with an aldehyde, particularly of phenol with formaldehyde, resistant to solvent and water, non-recyclable, permanent shape, cannot be reformed.
  • Phloxine (magenta)
    A fugitive organic dyestuff used to produce brilliant red color; a bluish red pigment used in process color screen printing inks; also refer to eosin.
  • Phosphate glass
    A type of glass where the glass former is phosphorous pentoxide instead of silicone.
  • Phosphor
    material that emits light when irradiated by cathode ray or when placed in an electrical field.
  • Phosphorescence
    (1) A property of a certain class of films or coatings which utilizes the effect of light on chemical elements (phosphors) within the structure of the product to provide a visible color in the absence of a normal light source; (2) The luminous appearance of objects having this property.
  • Photo mask
    (1) A manually produced opaque design on masking film for preventing exposure of predetermined areas of photographic film or stencil material; (2) A photographically produced duplicate of a halftone negative or positive with very thin density, designed to add slight density to the halftone film from which it was made to reduce future exposure effects in controlling color density in the final printing.
  • Photo multiplier tube (PMT)
    A single image receiver in a drum scanner; yields better shadow detail.
  • Photo YCC
    A color standard established by Eastman Kodak that is used to define color space.