Aquatint

Aquatint is an intaglio process in which the plate is covered with grains of rosin called an aquatint ground, which are then fused to the plate, generally by heating. The plate is immersed in an acid bath allowing acid to bite into the entire area pitted with the rosin, creating an overall grainy effect. This technique is often used to create tonal areas of colour or shading to capture the same effect as watercolour, hence its name.