Etching: Step 4

Aquatinting: The plate is covered with a coating of a fine resin dust (nowadays a healthier wax substitute is used) which turns into tiny globules when heated. To achieve the several tones of grey in the final print, the plate is immersed in the acid several times. The aquatint is progressively ‘stopped out’ after each immersion in the acid, using the varnish to protect the lighter tones from the acid.