Etching is one of several methods of printmaking that fall under the general category of intaglio (also included are engraving, drypoint, mezzotint, and aquatint). In each method the surface of a metal plate (usually copper or zinc) is abraded with a tool or through the corrosive action of some kind of acid. Engraving, drypoint, and mezzotint all use a tool to directly remove or abrade some of the metal plate. Etchings are produced when a corrosive resistant coating is placed over the plate. A sharp tool is used to remove lines in that coating (but not the metal itself). The exposed surface areas are bitten into the plate when it is placed into the acid. All intaglio techniques are printed the same way. Ink is pushed into the recesses of the plate and then the uppermost surface is wiped clean. Dampened paper is placed on top of the inked plate and then run through a press with several cushioning felt blankets. The pressure pushes the paper into the inked lines and recesses of the plate so that an image is transferred to the paper.