Aquatint is a printmaking technique that is a variation on etching. One applies acid to a zinc or copper plate to form marks that will hold ink. A sheet of paper is passed through a printing press with the ink-laden plate, transferring the ink to the paper. With an aquatint, however, instead of ink, an acid-resistant, powdered rosin is used to create tonal variations, resulting in an image having tones similar to watercolor washes. Note that the term aquatint applies to the technique itself, as well as the resulting print.