Etching, also called a line etching, by definition, is a method of printmaking where the design is drawn on a metal plate through a layer of acid-resistant wax. The plate is dipped in acid, which bites into the exposed lines, thus etching the design into the plate. German artist Daniel Hopfer is believed to be the first to use etching in printmaking, although the process was likely used earlier, around the 14th century as a method of making decorations on armor. Some of the most famous artists of all time have used this expressive method of creating prints including Rembrandt, Francisco Goya and Salvador Dali. Beautiful etching prints can be found on AbeBooks, including a signed etching by David Hockney, one of only 10 artist's proofs.