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.
  • 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.
  • Specific strength
    Ultimate tensile strength divided by material density.
  • Specific viscosity
    Of a polymer, the relative viscosity of a solution of known concentration, minus one.
  • Specific volume
    Of paper, the volume per unit mass, under specified conditions; expressed in cubic centimeters per gram.
  • Specification
    A clear and accurate description of the technical requirement for materials, products, or services; a descriptive reference or a detailed itemized description of dimensions, plans, materials, and other requirements; the document that prescribes the requirements that the product or service has to meet.
  • Specification for non-heatset advertising printing (SNAP)
    A set of standards for color separation and proofing developed for printing with uncoated paper and newsprint stock (USA).
  • Specification for web offset publications (SWOP)
    A set of standards for color separation films and color proofing developed for publication printing and magazine printers.
  • Speck
    A small spot, mark, or discoloration.
  • Specking
    A black spot that appears after firing, caused from dust and lint settling on a wet decoration prior to firing.
  • Speckle
    A pixel that is abnormally lighter than the surrounding area.
  • Spectral curve
    A curve that shows the specific amount of light at each wavelength transmitted by or reflected from a material, describing it just as the spectral energy distribution curve describes a source of light. (A fingerprint of a color).
  • Spectral energy distribution curve
    The amount of relative energy or light of a specific light source, emitted at each wavelength plotted against the wavelength of visible light (380 Nm to 760 Nm).
  • Spectral highlight
    The brightest white possible on a film or substrate.
  • Spectral reflectance
    The relative amount of light reflected from a surface.
  • Spectral sensitivity
    The relationship between the radiant sensitivity and the wavelength of the incident light.
  • Spectral transmittance
    The reflected light bands effected during radiation curing of dispersed pigments, (directly) affecting the absorption of radiation of the ink dispersion.
  • Spectrodensitometer
    A spectrally based densitometer that combines the functions of a spectrophotometer, colorimeter, and densitometer.
  • Spectrogram
    A diagram showing the relative sensitivity of a photographic material to different wavelengths or colors of light.
  • Spectrophotometer
    Photometric device for the measurement of spectral transmittance, spectral reflection, or relative spectral emittance.
  • Spectro-radiometer
    A device for determining the distribution and intensity of radiation, especially infrared.