Glossary

The PRINTING United Alliance Glossary serves as an excellent industry terminology resource. It is the language by which we all communicate. Without it, universal understanding would be impossible.

To keep our constituents well informed about changes to the increasingly complex industry terminology, PRINTING United Alliance has developed this glossary of terms. 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.
  • Offset stock
    Paper manufactured to accept offset printing ink; also referred to as offset paper and uncoated book paper.
  • Ogee
    A distortion of an image using an S-shaped curve as one baseline, gives image a wavy look.
  • Ohm
    Unit of electrical resistance used for measuring or testing the capacity of resistance; the unit of resistance equivalent to the resistance of a conductor in which one volt produces a current of one ampere.
  • Ohmeter
    An instrument used for measuring electrical resistance in ohms.
  • Ohm's Law
    The current in a circuit is directly proportional to the voltage E, and inversely proportional to the resistance R: E=IR, I=E/R. R=E/I.
  • Ohms per square
    A means of evaluating the resistance value of an ink mixture, or the resistance value of a square of ink one mil thick.
  • Oil absorption
    The quantity of oil required to completely wet a definite weight of a given pigment, forming a paste.
  • Oil soluble resin
    A resin that will dissolve in a drying oil at slightly elevated temperature to yield an homogenous film.
  • Oil-in-water emulsion
    An emulsion that has water as the external phase and an oil as the internal phase.
  • Oiticica
    A drying oil used in ink formulations made from seeds of licahia rigida tree; similar in properties to tung oil.
  • OJT
    Acceptable acronym for on-the-job.
  • OK sheet
    A press sheet that closely matches the original proof and has been approved by the customer, used as a guide to judge print quality as production run progresses.
  • Olefin
    A chemical family of unsaturated hydrocarbons; also refer to polyolefin.
  • Oleo resinous
    Describes solvents or inks derived from crude oil, or having vehicles compounded from crude oil derivatives.
  • Olephilic
    Oil receptive.
  • Olephobic
    Oil repellent.
  • Oligomer
    (1) A multiple unit molecule consisting of several monomeric units in chemical union; (2) Base resin used in UV ink formulations.
  • On-contact printing
    Screen printing with the print screen in contact with the substrate both during and after printing.
  • On-Demand Color (ODC)
    This term typically refers to short run color printing. These processes include ink-jet, electrostatic and direct-to-press.
  • One-man squeegee
    A squeegee mounted on a counter balanced device so that the operation of very large squeegees can be accomplished with a minimum of effort.
  • One-side finish
    Paper finished on one side only.
  • One-way screen
    A halftone screen having lines running in one direction only.
  • Oozing adhesive
    Adhesive that is forced out from between the face film and backing sheet of pressure sensitive laminates by pressure in die or guillotine cutting.
  • Op art
    Art form using arbitrary patterns of shape, color, and value to create optical illusions or effects that suggest movement.
  • Opacifier
    A chemical agent added to a material to make it opaque.