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.
  • Solvent
    A dissolving, thinning, or reducing agent.
  • Solvent activated
    An adhesive that requires the addition of a solvent to activate bonding properties.
  • Solvent attack
    An effect or change in a material when contacted by a solvent. 
  • Solvent dispersion
    An ink where pigment is dispersed in a solvent solution containing a solvent-soluble binding agent.
  • Solvent evaporation
    Vaporizing of liquid solvent, resulting in their removal from a printed film.
  • Solvent release
    The evaporation of a solvent during ink drying.
  • Solvent resistance
    The resistance of a printed area and/or the substrate to the dissolving action of specified organic liquids.
  • Solvent rewettable (solvent reactivation)
    (1) A dry ink imprint that can be changed back to the wet state by introduction of a solvent; (2) A dry film that can be rewetted and removed by saturating with solvent.
  • Solvent strength (solvent power)
    The ability of a solvent to dissolve materials.
  • Solvent-evaporating ink
    Ink that is dried by allowing the solvent to vaporize either in ambient or elevated temperature conditions.
  • SOP
    Acceptable acronym for standard operating procedure.
  • Souring
    The precipitation or coagulation of the ingredients in an ink due to contamination by water or other foreign material.
  • Soya oil (soybean oil)
    A vegetable oil used in the preparation of certain ink vehicles.
  • Spacer
    The separator between switch matrices in a membrane switch.
  • Spacer easel
    An easel that positions and locks two or more vertical parts of a display into a set-up position.
  • SPAI
    Acceptable acronym for Screen Printing Association International, the former name for the Specialty Graphic Imaging Association (SGIA) headquartered in Fairfax Virginia USA.
  • Spalling
    A defect in vitreous enamel characterized by the chipping or fragmenting of the surface coating, caused by coefficient of thermal expansion or contraction.
  • Span
    The difference between the upper and lower limits of a range.
  • Spandel
    A flat glass that is sometimes decorated for architectural use.
  • Spatial resolution
    The smallest feature of an image that can be detected as a fraction of the total image.
  • Specialty paper
    Papers that typically contain 25 to 100% rag, or are polymeric coated, cast coated, or are high gloss.
  • Specific adhesion
    The force required to remove a decal adhesive from a specified substrate under specified conditions.
  • Specific gravity (sp gr)
    (1) The weight per volume of a material compared to water, less than 1.0, the material floats, greater than 1.0 and it sinks; (2) For solids and liquids, the ratio of the density of a material to the density of an equal volume of distilled water at a specified temperature; (3) For gases, the ratio of the density of a gas to the density of air; (4) The density mass per unit volume of any material divided by that of water at the standard temperature (4°C). 
  • Specific heat
    The amount of heat required to raise a unit weight of material one degree of temperature, expressed as calories/gm/°C or Btu/lb/°F; ratio of material’s thermal capacity to that of water at 15°C.
  • Specific modulus
    Young’s modulus divided by material density.