Lefranc & Bourgeois Charbonnel Hard Black Ball Ground

a20791713c15c52a085ce3_mContains: judea bitumen, dammar resin, wax.

Dry extract: 100%
Finish: opaque matt
Hardness: hard, not quite as hard as Charbonnel hard black ball ground.
Consistency: paste
Characteristics: The matt black finish obtained makes etching work very clear.
How To Use: Wrapped in a piece of taffeta which serves as a filter, the ball is rubbed on the pre-heated metal plate. Dab on the ground to obtain an even surface before smoking.
Plate Cleaning: Before applying these grounds, it is imperative that all grease be removed from the plate. To do this, thin some Marly white with a small quantity of water and rub the plate with a soft cloth or a piece of cotton. Rinse under flowing water. Pour a soured solution of vinegar and salt on the plate. Rinse once again. Dry rapidly. Avoid putting fingers on the plate whilst carrying out these operations.
Hard Grounds: Once the ground is applied and dry, the picture is etched with a hard point in order to expose the metal beneath the ground. The plate is then placed in a bath of acid to erode the exposed metal. Once the required bite depth has been attained, the plate should be taken out of the acid bath solution and dried and the ground removed with the appropriate thinner.