Aquatint:

An etching process in which tone is created by treating a plate with fine particles of acid-resistant materials (like powdered resin) and then placing the plate in an acid bath. The acid bites into the plate between the grains of resin and, when printed, the mass of tiny spots produces a textured area with tonal effects similar to watercolor wash.

Lithography:

A planographic prinitng process where a drawing is made directly on a stone or other smooth matrix with greasy materials such as lithographic crayon. The surface is then dampened with water, which is repelled by the greasy areas. The surface is then rolled with prining ink which adheres only to the greasy areas and is itself repelled by the areas which have water. The drawn image is then printed.

Pochoir:

A printing process using stencils, originally used to simulate handcoloring.