Glossary Of Terms

The PRINTING United Alliance 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. PRINTING United Alliance 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 PRINTING United Alliance assumes no responsibility for the use of information presented herein.


  • Alphabet length
    The space required for the letters of the alphabet in a particular type font.
  • Alphabet sheet
    Sheet containing fonts of letters that may be removed and relocated to form words and/or lines of copy. (They are either on transparent material having a pressure sensitive adhesive back, or the letters are printed on the back of the sheet and adhered to the new substrate by burnishing).
  • Alphanumeric
    Consisting of alphabetic and numerical symbols; a device or system that includes letters and numbers.
  • Alter
    A change made to an image element, color, or page layout through computer manipulation.
  • Alteration
    Change in copy or specification made after production has begun.
  • Alternating current (AC)
    Electric current that periodically reverses the direction of electron flow.
  • Alternative method
    Within the meaning of the Clean Air Act (US), any method of sampling and/or analyzing for an air pollutant, which is not a reference (or equivalent) method, but which has been demonstrated to produce results adequate for the determination of compliance with the Act.
  • Alumina
    Any of several forms of aluminum oxide used as an abrasive and in marking glass, enamel, and refractories.
  • Alumina hydrate
    A white inorganic pigment used as an extender in inks and noted for its transparency.
  • Aluminum bronze
    Finely pulverized aluminum in very small flake form suitable for mixing with a varnish type or lacquer type vehicle for use in screen printing metallic effects.
  • Aluminum ink
    A printing ink whose principal pigment consists of aluminum, finely pulverized into flaky particles, and when printed gives a silver color appearance; also referred to as silver ink.
  • Aluminum stearate (oxide)
    A principal thickening agent used in many screen printing inks and transparent extender bases.
  • AMAL
    Acceptable abbreviation for amalgam.
  • Ambient
    Surrounding environmental conditions such as pressure, temperature, or humidity; environment coming into contact with a system or component.
  • Ambient compensation
    The design of an instrument such that changes in ambient temperature do not affect the reading.
  • Ambient temperature
    Temperature of the immediately surrounding air volume.
  • American National Standards Institute (ANSI)
    A standards setting agency of the United States that approves design and performance of electrical/electronic components (USA), formerly the American Standard Association.
  • American Society for Testing & Materials (ASTM)
    The world’s largest source of voluntary consensus standards on the characteristics and performance of materials (USA).
  • American Wire Gauge (AWG)
    A wire diameter specification where the smaller the number designator, the larger the wire diameter.
  • Amine resin
    Synthetic resin derived from the reaction of urea thiourea, melamine, or allied compounds with aldehydes, particularly formaldehyde.
  • Ammonium bichromate (ammonium dichromate)
    A compound or salt used for rendering colloids or emulsions active to actinic light such as in photostencils.
  • Ammonium fixer
    Photography, a fixing bath containing NH4+ (univalent ion of ammonia) that is used for removing silver halides from photosensitive emulsions.
  • Ampere (A, amp)
    A standard unit of current produced by one coulomb of charge passing a point in one second.
  • Amphoteric
    Capable of acting either as an acid or base.
  • Ampule (ampoule)
    A small hermetically sealed glass container that is designed to be filled and then sealed by fusion of the glass neck.