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.


  • Object
    A graphic or picture that is embedded in a document file using object linking and embedding (OLE).
  • Object color
    The aspect of the appearance of an object dependent upon the spectral composition of the incident light, the spectral reflectance or transmittance of the object, and the spectral response of an observer.
  • Object linking and embedding (OLE)
    A standard method for inserting an object into a document, where the document retains a connection or link with its original program.
  • Object oriented
    A graphic image that is created with mathematical descriptions instead of pixels.
  • Obliteration
    The ability of an opaque overprint to hide completely the color underneath; also sometimes referred to as obliterating power.
  • Obscure
    Glass that has been made translucent by grinding, sandblasting, or acid etching.
  • Obsidian
    A natural glass that is produced by volcanic action.
  • Occupational exposure limit (OEL)
    Minimum allowable concentration of toxic substances in workroom air to protect workers who are exposed to toxic substances over a working lifetime.
  • Occupational Safety and Health Act (OSHA)
    A US federal law enacted in 1970 to protect workers from industrial hazards.
  • Ochre
    A naturally occurring yellow iron oxide used as a pigment in ink formulations.
  • OCR ink
    Ink that is composed of low reflectance pigments such as carbon black that can be read by OCR equipment.
  • OD
    Outside dimension of an item.
  • ODC
    Acceptable acronym for ozone depleting chemical or compound.
  • Off color
    Color variation from a sample or specification.
  • Off contact distance
    The space between the bottom of the screen and the top of the substrate; also refer to snap-off.
  • Off contact printing
    Screen printing with the print screen adjusted slightly above the substrate so that it does not make contact with the substrate except during printing.
  • Off square
    A material where two or more corners deviate from an exact 90° angle.
  • Offset (offsetting)
    (1) An indirect printing form; (2) The unintentional transfer of ink to the bottom of the printing screen, the back of a succeeding sheet, or other undesired surface.
  • Offset paper
    A grade of paper manufactured in a range of weights in white or light colors with good dimensional stability, cleanliness, and pick resistance; alterative term for uncoated book paper.
  • Offset printing
    Planographic printing by indirect image transfer.
  • Offset stock
    Paper manufactured to accept offset printing ink; also referred to as offset paper and uncoated book paper.
  • Ogee
    A distortion of an image using an S-shaped curve as one baseline, gives image a wavy look.
  • Ohm
    Unit of electrical resistance used for measuring or testing the capacity of resistance; the unit of resistance equivalent to the resistance of a conductor in which one volt produces a current of one ampere.
  • Ohmeter
    An instrument used for measuring electrical resistance in ohms.
  • Ohm's Law
    The current in a circuit is directly proportional to the voltage E, and inversely proportional to the resistance R: E=IR, I=E/R. R=E/I.