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.


  • Jack knife easel
    An easel that can be folded, but retains its intended support strength when in use.
  • Jaggies
    (1) Slight noticeable unwanted angles that are apparent on a cut line or curve that would otherwise be smooth; (2) An effect caused by images or lines being rendered at too low a resolution that makes edges rough or stair-stepped.
  • JAN
    Acceptable acronym for Joint Army Navy specification (US).
  • Japan
    A varnish yielding a hard, glossy film when baked at high temperature.
  • Jar mill
    A small ball mill used for extremely small batch grinding; refer to ball mill.
  • Jasper ware
    A vitreous, opaque, colored, unglazed ceramic ware containing substantial amount of barite.
  • Jelling
    The thickening of an ink or other liquid that cannot be reversed by stirring; refer to gel.
  • Jet
    (1) The blackness or intensity of the masstone of black or near-black ink or colored surface; (2) A pressurized stream of air used as a drying mechanism.
  • Jet dryer
    A mechanical unit consisting of a conveyor belt for transporting wet prints through a chamber where hot air is projected through holes or slits onto the surface of the print to hasten evaporation of the volatile solvents from the wet ink film.
  • Jet drying
    The drying of screen printed material by means of a jet dryer.
  • Jet spray etcher
    A device for etching printed circuit boards by means of the application of etchants through a nozzle, rather than by immersion.
  • Jig
    Any special form or fixture constructed to support and hold in place a part during printing or converting.
  • Jigger
    A machine similar to a potter’s wheel used for shaping flatware by means of a profiled tool at a fixed distance from the rotating surface of a plaster mold.
  • Job shop
    A commercial printing company.
  • Jog
    (1) Close interval starting and stopping of a press to attain position for set-up, cleaning, trouble shooting, etc.; (2) To align sheets of paper into a compact pile to a common edge either manually or by vibration.
  • Jogger
    Mechanical device to hold sheets for jogging with the holding platform slanted toward one corner and with the lower edges fitted with metal or wood stops against which two edges of the sheet can be positioned by vibration of the holding platform.
  • Joint
    The junction of two structural members of a screen printing frame, such as butt, lap, and dovetail attachment styles.
  • Joint Photographic Electronic Group (JPEG)
    A common standard for compressing image data.
  • Jolly
    A partly or fully automatic device similar to potter’s wheel that utilizes molds for making cups.
  • Jordan machine
    A conical rotor and housing that mechanically bruises the pulp causing fibrillation and hydration while serving to produce a more uniform mixture of water, fibers, and other additives improving sheet formation in papermaking; better known by its nickname beater.
  • Joule
    A unit of energy or work that is equivalent to one watt per second or 0.737 foot-pounds; a calorie is equal to 4.184 joules.
  • Junior outdoor poster
    A smaller outdoor poster approximately 60" x 132", usually consisting of three or fewer sheets.
  • Justify
    To space out lines of type uniformly to a desired length, refers to aligning both the right and left hand margins.
  • Just-In-Time (JIT)
    A manufacturing method based on statistical process control, setup procedures, yield quality, and preventive maintenance.
  • Just-noticeable-difference
    In the CIELAB color model, a difference in hue, chroma, or intensity, or some combination of all three, that is apparent to a trained observer under ideal lighting conditions.