Etching Ground

Syn. Etching varnish . Prep. 1. Beeswax, 5 parts; linseed oil, 1 part; melted together. 2. (Callot’s Hard varnish , Florentine v. , Florence v. ) From linseed oil and mastic, equal parts, melted together. 3. (Callot’s Soft varnish .) From linseed oil, 4 oz.; gum benzoin and white wax, of each 1 ⁄ 2 oz.; boil to two thirds. 4. (Lawrence.) White wax, 2 oz.; black pitch and Burgundy pitch, of each 1 ⁄ 2 oz.; melt, add by degrees, of powdered asphaltum, 2 oz.; and boil together, until a piece, when thoroughly cold, will break by being bent double 2 or 3 times between the fingers; next pour it into warm water, make it into small balls, and place each of them in a piece of taffety for use. Obs. The preceding compositions are applied to the surface of the plates, previously made sufficiently warm to melt them easily, their even diffusion being promoted by dabbing them with a wad of cotton. Those that are white are then generally blackened on the surface by skilfully pa ing them over the smoky flame of one or more candles, by which the marks of the etching point on the bright metal are rendered the more visible.