ELECTROTYPE, a metallic copy, made by electro-deposition, a form of type, a ((cut,' engraving, etc., and manufactured into proper shape for printing. Wax is heated in a kettle, poured out on a molding-case and placed in a press to receive a reverse impression of the form, engraving, etc. The face of the wax mold is covered with plumbago to give it a conducting surface to which the metal will ad here. The negative pole of a battery is attached to the mold and the positive to a piece of copper (or occasionally nickel or iron) and both are placed in a bath of sulphate of copper in solution. The copper is deposited on the face of the mold in a thin film, which increases in thickness as the process continues. The shell having attained the thickness of a stout sheet of paper the mold is removed from the bath. the shell detached and strengthened by a backing of electrotype metal, this being a composition of lead, tin and perhaps a little antimony. The
electrotype shell being washed is laid face down on a metal surface and a sheet of tin foil melted on to the back, after which the backing metal is poured on in a molten condition. Afjer cool ing, the electrotype plate goes to a planer, shaver, trimmer, etc., until reduced to the proper form for printing. Later it is remounted on a base of wood or metal to bring it to the same height as type, that it may be printed in a form with type; or sometimes the plate is curved ui a bending machine for rotary printing. For details of the electric bath employed, see ELEC TROCHEMISTRY. When the copper electrotype is faced with nickel it is sometimes called nickel type, or if with iron, steeltype. The electrotype plate has almost wholly superseded the stereo type for book and miscellaneous printing, though the stereotype is retained for rotary newspaper printing.