Charbonnel Ultraflex Liquid Ground Engraver 75ml

Apply it cold to the plate with a very supple brush, or plate coating device or pour it directly onto the inclined plate. 
Plate Cleaning: Before applying these grounds, it is imperative that all grease be removed from the plate. To do this, thin some Marly white (whiting) 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.