Ground
Ground. Preparing a surface in metal working for some further action or the surface itself. In etching the ground is a gummy substance spread over a metal plate to preclude the acid from etching that area. In repoussé it is the surface itself from which the metal rises to form the detail. Like painting and drawing where a ground is a prepared surface, a ground is necessary for both etching and repoussé The ground in acid etching, composed of beeswax, resin and bitumen (or sometimes asphalt), performs a stop-off function where the ground has not been removed. (Other stop-off can be done with stop-off lacquer or stop-off varnish.)
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