NNP

Acid Dip.  A method of cleaning metal by immersing in a mild acid solution. It is used in medallic work as a bright dip, certain finishing operations, or in cleaning. Also called acid bath.  See pickle, pickling.

This unusual acid-etched medal was made by photoetching from black-and-white images. Etched on one side of an aluminum sheet, it is turned over for etching the reverse with exact positioning. Numerous pieces are arranged on a large plate. Color is added by paint in the sunken etched areas. It is not a popular method of medal manufacture.

excerpted with permission from

An Encyclopedia of Coin and Medal Technology

For Artists, Makers, Collectors and Curators

COMPILED AND WRITTEN BY D. WAYNE JOHNSON

Roger W. Burdette, Editor