Etching: preparing the plate
1. A metal plate (usually zinc or copper) is covered evenly with an acid-resistant coating called a ground.
2. Using an etching needle, the artist draws an image into the ground, exposing the underlying metal.
3. The plate is then immersed in an acid bath, where any exposed metal is etched by the biting action of the acid.
4. The depth of the line or open area is controlled by the amount of time the plate is exposed to the acid. The deeper the lines are etched, the more ink they will hold, resulting in darker line-work when the plate is printed. In the aquatint etching process tonal values can be created by applying< an evenly pitted textural surface to the plate.
5. Once the plate is etched to the artist's satisfaction, the ground is removed.