The story
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A style of engraving in relief by means of voltaic electricity. A picture is drawn on a metallic plate with some material which resists the fluids of a battery; so that, in electrotyping, the parts not covered by the varnish, etc., receive a deposition of metal, and produce the required copy in intaglio. A cast of this is then the plate for printing. Full definition →
Etymology from Wiktionary, CC BY-SA 4.0.