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.
  • Bar
    A standard unit of pressure equal to 105 newtons per square meter or 0.98697 standard atmosphere.
  • Barcol hardness
    A hardness value obtained by measuring the resistance to penetration of a sharp steel point under a spring load, gives direct readings on a 0 to 100 scale; also refer to Shore hardness.
  • Barium crown glass
    An optical glass containing soda (Na2O), lime (CaO), and silica (silicon dioxide) composites.
  • Barium flint glass
    An optical glass containing 45 to 65% lead oxide.
  • Barium oxide
    Derived from BaCO3 (witherite) used principally in optical and crystal glass instead of lime or red lead.
  • Barre
    A stripe-like pattern in woven fabric, parallel to the weft threads, and usually caused by dye differences in the fibers or physical differences in thread geometry.
  • Barrel distortion
    Image effect that spreads the center dimensions of the picture.
  • Barrier coat (primer) (sealer coat)
    A coating applied to face material to provide increased opacity to the face material and/or to prevent migration between adhesive and face material and to improve anchorage of adhesives to face material.
  • Barrier tape
    Reflective pressure sensitive strips printed with diagonal strips of red transparent ink for application to rear/side of a vehicle or to a street barrier, warning, or safety signal.
  • Barytes
    A colorless crystalline mineral of barium sulfate used as an ink pigment, extender, or filler.
  • Calibration bar
    A strip of tones attached to a negative, proof, or print used to check print quality.
  • Color bar
    A measurement device printed in the trim area consisting of test targets to measure print attributes such as dot gain, density, slur, doubling, contrast, and trapping.
  • Draw bar frame
    A metal channel that holds a moveable bar within each side of a screen frame. Mesh is attached to the bars and the bars are moved by turning the adjustment screws to apply tension).
  • Floating bar printing frame
    A rigidly assembled screen printing frame which has extra, adjustable bars inside of two of the rigid sides, attached with bolts and wing nuts. The fabric is attached to the movable bars by which tension can be added, or register of the stencil adjusted.
  • Flood bar (return-blade)
    A device on a screen printing press comprised of a thin metal (or plastic) blade, which has the function of spreading a thin film of ink uniformly over the printing screen, in the opposite direction of and preceding the printing stroke.
  • Mayer rod/bar
    A metal rod wound with a fine wire around its axis, used to draw an ink down evenly and at a given thickness.
  • Optical mark reader (OMR) (optical bar reader) (optical bar recognition) (OBR)
    Electronic equipment that scans, interprets, and converts bar coded information into a machine readable form.
  • Stretcher bars
    Pneumatic device for clamping to the edges of screen printing mesh in order to stretch the mesh over the frame.