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: Webster's Revised Unabridged Dictionary (1913)