Final answer:
In etching, a matrix is covered with wax and etched with a design, then submerged in an acid bath to create incised lines for printing. Aquatint uses a resin to achieve tonal variation.
Step-by-step explanation:
Etching is an intaglio process in which the matrix is covered with a waxy substance, and the design is drawn into this substance. The etched drawing is then put into an acid bath. This acid bath process etches the exposed metal lines, after which, the plate is removed, cleaned, and prepared for printing. Inking the plate, wiping it, and then printing it creates an image from the ink in the etched channels, with tonal quality dependent on the time the plate spent in the acid. Aquatint is a variation of etching that employs a resin to create tonal effects on the metal plate for a more painterly finish.