Aquatint is the most flexible and precise method of creating tones in etching. Grains of rosin are dusted onto a plate, then melted slightly, so that the rosin can create tiny islands for acid to bite around. Aquatint provides a texture, or tooth, to hold the ink. If the rosin grains are evenly spaced, and you bite the plate deeply in an acid bath, aquatint can provide a black like no other in any medium. In addition, once you have an aquatint ground on the plate, you can create many different tones of gray and many different kinds of marks.