Electrochemistry
The Elektrochemitypie is one of Joß in Karlsruhe developed process for the production of printing and embossing plates made of steel , bronze or brass by means of chemical etching. The transfer of the print image to the polished metal plate is mostly done by a lithographic transfer , which is sprinkled with resin powder and slightly melted. The back of the metal plate is covered with an asphalt layer against the acid . The etching process now takes place in such a way that the plate to be etched, on the one hand, and a metal or carbon plate placed parallel to it, on the other hand, interact as electrodes of a galvanic current in an acid bath. This galvanic bath is only used to etch the plate, while the subsequent deep, round and clean etching is carried out as in zincography . With this method, a greater fineness of the drawing of the print image is preserved, in that the fine lines are protected more effectively against the attack of the etching liquid by scattering and melting a resin powder than is the case with the usual zincographic method.