Glossary Of Terms

The SGIA 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. SGIA 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 SGIA assumes no responsibility for the use of information presented herein.


  • Thermal stress
    Cracking or crazing of a thermoplastic material from exposure to high temperatures.
  • Thermal transfer printer
    A machine that digitally prints by transferring inks (resin or wax) from a foil or ribbon onto a media.
  • Thermal wax printer
    A medium-resolution color output device that must first separate the color information for continuous tone and spot color into three or four primaries, and are printed in multiple passes, one for each color. A/k/a thermal wax transfer.
  • Thermal zero shift
    An error due to changes in ambient temperature where the zero pressure output shifts, moving the entire calibration curve in a parallel displacement.
  • Thermistor
    A resistor composed of semiconductors having resistance that varies rapidly and predictably with temperature. (Thermistors usually have negative temperature coefficients and are often used as a temperature controller in a dryer).
  • Thermochromatic ink
    Ink that is designed to change or loose color when the ambient temperature is increased, formulated to shift at different temperature levels, and to shift back to original color when the ambient temperature is reduced.
  • Thermocouple
    An instrument for measuring temperature difference, usually constructed of two dissimilar joined metals for producing a thermo-electric current that is transmitted to a scale for direct reading.
  • Thermoforming (heat forming)
    Process for forming a sheet of plastic into a three- dimensional shape through the application of heat and pressure, also refer to vacuum forming.
  • Thermographic paper
    A substrate where the image is formed by an irreversible chemical change that occurs when heat is applied or as a result of a physical change that occurs in a thin coating over the sheet.
  • Thermography (raised printing)
    A printing process where the ink, while still wet, is dusted with a resinous powder that adheres to the ink, which is then heat treated causing the powder particles to fuse together giving a raised effect.
  • Thermoplastic (TP)
    Plastic material that can be made to flow repeatedly with the application of heat; to become soft when heated and solid when cool.
  • Thermoplastic adhesive
    A double-layered flock transfers with an additional coating of adhesive, between the silicon coated paper and the plastisol layer (flock adhesive).
  • Thermoplastic toner
    Resin particles melted by heat that are cooled to form a solid.
  • Thermoset
    A type of plastic that under the influence of heat softens and then becomes permanently set and infusible when cooled; a plastic material that once cured cannot be made to reform.
  • Thermosetting ink
    Ink that polymerize to a permanently solid and infusible state upon application of heat and subsequent cooling.
  • Thick film circuit (printed and fired circuit)
    Circuits consisting of screen printed patterns of conductive inks or coatings on ceramic substrates that are fired at high temperatures.
  • Thickener
    Inert composition formulated for intermixing with thin viscosity ink or dye to increase body or add bulk.
  • Thickness gauge
    A type of instrument used to determine the thickness of a stencil, screen mesh, or ink layer.
  • Thin film circuit
    Circuit made by printing conductors, resistors, and capacitors in a prescribed arrangement on a dielectric substrate, then adding complete prefabricated active components to the thin film structure. (The prescribed pattern may also be obtained by evaporating or sputtering certain materials in a vacuum by selectively masking undesired substrate areas).
  • Thin film ink
    Screen printing ink used in the production of thin deposit or etched electronic circuits.
  • Thin negative
    A negative that is underexposed or underdeveloped.
  • Thin stencil
    (1) A thin gauge film on a support sheet for knife-cutting; (2) An inadequately exposed photoscreen stencil or one that has been deliberately underexposed to obtain a film that is thinner than the available potential thickness.
  • Thinner
    A liquid that reduces viscosity, but does not impair the power of the solvent.
  • Thirty
    Symbol used in newspapers to designate the end of a story.
  • Thirty (30) sheet poster (billboard)
    Larger outdoor poster approximately 297 x 663 cm (117 x 261 inches), usually consisting of 12 sheets or less; refer to poster paper.