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.
  • Reflection (specular)
    Parallel incident rays that are reflected at a constant angle from a smooth surface.
  • Reflection densitometer
    Measures the amount of light that bounces off a print at 90º angle.
  • Reflective art
    Artwork either line or halftone that is rendered on an opaque surface.
  • Reflective beads
    Minute round particles of glass for embedding in an ink or adhesive film to act as a lens to reflect light rays.
  • Reflective copy
    Illustrative copy that is viewed by light reflected from its surface.
  • Reflective ink
    Ink containing microscopic glass spheres that have the capability of returning light rays to the observer.
  • Reflective sheeting
    Sheet material with one face treated with a substance, usually microscopic glass spheres that return light rays striking it.
  • Reflectivity
    The capacity of a surface to reflect light rays.
  • Reflex blue (alkali blue)
    A strong organic blue pigment with the highest tinctorial strength of any blue pigment.
  • Reflex copy
    The exposure of a photosensitive film by passing light through the back of the film, then through a positive or negative, and reflecting the light back from the support surface.
  • Reflex paper
    A light sensitive material for contacting same size reproductions.
  • Refractive index
    The deviation of light as it passes through a given substance, given as the ratio of its velocity in a vacuum to its velocity within the substance.
  • Refractometer
    An instrument for measuring indices of refraction.
  • Refractory
    A material that has a relatively high melting temperature and is capable of enduring continuous high temperature.
  • Register (in register)
    (1) To precisely align either manually or automatically one print color to another; (2) A mark on a design that identifies it as having been officially recorded with the US Patent Office.
  • Register bond
    A common lightweight writing paper designed for single- and multi-copy business forms.
  • Register check
    A mylar roll material that is coated with a light adhesive used to determine registration without printing a actual production sheet or part.
  • Register device
    A mechanical device used to align a design elements prior to or during printing.
  • Register guide (feed guides, three-point lay)
    Physical stops, usually three in number, placed on the printing base in relation to two adjacent edges of the printing sheet to ensure proper positioning for printing; also called feed guides.
  • Register guides
    Stops on the printing base against which edges of substrate are placed for printing to ensure that all substrates are being printed in identical areas or positions.
  • Register locking system
    A mechanical system where a printing screen and its printing base can be locked into position after adjustment to accomplish register.
  • Register mark
    A crosshair or other target image applied to original copy as an aid for positioning and aligning purposes.
  • Register punch
    A device used to cut holes in film flats to ensure registration.
  • Registered numbers
    Heat-applied numbers that are centered on a transfer sheet of paper with precision.
  • Registrar
    A company that conducts quality system assessments to recognized quality system standards or set of requirements.