Source : Webster's Revised Unabridged Dictionary (1913)

Copperplate \Cop"per*plate`\ (k[o^]p"p[~e]r*pl[=a]t`), n.
   (a) A plate of polished copper on which a design or writing
       is engraved.
   (b) An impression on paper taken from such a plate.

   Note: In printing from a copper- or steel plate the lines are
         filled with ink, the surface of the plate is wiped
         clean, the paper laid upon it, and the impression taken
         by pressing it under the roller of a plate press.

   {Copperplate press}. See {Plate press}, under {Plate}.

Source : WordNet®

copperplate
     n 1: a fine style of handwriting based on the writing used on
          copperplate engravings
     2: a print made from an engraved copperplate
     3: an engraving consisting of a smooth plate of copper that has
        been etched or engraved