Etching is a process used by artists to make several copies of a drawing. The copies are printed from a metal plate on which a drawing has been etched (eaten in with acid). Invented in Germany in the 16th century, etching is probably used more by artists than any other print making method. It allows greater freedom than most other methods, because drawing on an etching plate is much like drawing with an ordinary pencil on paper. Such artists as Rembrandt, Goya, and Whistler were great etchers as well as great painters.
Prints that are made from an etched plate are called etchings. An edition refers to the number of etchings made from one plate: often an edition is from 10 to 50 prints, but it can be fewer or many more. To make an etching, the artist uses a metal plate of copper or zinc. The plate is covered with ground, an acid-resisting substance made of asphalt, varnish, and beeswax. When the ground dries, the artist draws on it with an etching needle. This tool can be made of any pointed instrument--a key, a dentist's pick, or a sewing needle taped to a stick. In drawing, the artist scratches the ground away from the plate, exposing the metal. The plate is then placed in a bath of acid. The acid eats away at the exposed metal but cannot affect the plate where it has been covered with ground. The longer the plate is left in the acid, the deeper the grooves become. The darkness of the lines depends on the depth of the grooves. If some lines are to be light and some dark, the artist removes the plate from the bath after a moment or two, covers with ground the lines that are to be printed light, and puts the plate back.
Sometimes, while working on a plate, the artist will want to see what has been done so far. To make a proof (sample print), the ground is removed from the plate with solvent, a liquid that dissolves wax or varnish. A loose, creamy ink is then dabbed over the plate, filling the etched grooves. The ink is wiped off the surface of the plate with a dry, stiff piece of fabric called tarlatan. The plate is covered with a slightly damp sheet of paper and soft felt blanket and is run through a printing press. The great pressure of the press forces the paper into the grooves to absorb the ink. If the artist decides that the plate needs more work, new lines can be added by covering the plate with ground.
Aquatint is an etching process by which solid areas of grays and blacks can be created. The artist wraps crushed resin--a brittle, natural substance that looks somewhat like small yellow rocks—in a piece of cloth. The resin bag is held over the plate and is tapped gently, forcing grains of resin through the fabric and onto the plate. The plate is then heated. Heating causes the grains of resin to melt and stick to the plate. When the plate has cooled, it is dipped in the acid bath. The acid eats into the plate in between the grains of resin. The artist removes the plate and uses varnish to cover the areas that are to be light gray. Then the plate is put into the bath again. This process is repeated several times until the plate makes a print with a variety of grays. By using different kinds of fabric for the bag, the artist can also vary the texture of the grays. Aquatint can also be used to make colored etchings. A different plate is used for each color.
When petroleum jelly or tallow (animal fat) is added to regular ground, a soft ground that never dries is formed. A line scratched through soft ground is not as sharp as a line cut through regular ground; instead it is soft and fuzzy. The artist can place a piece of paper over the soft ground and draw on the paper with a pencil. The ground under the pencil lines sticks to the paper, so that when the paper is removed, the metal is exposed under the drawing. The remaining steps are the same as in hard-ground etching. By using several different kinds of pencils and differently textured paper, the artist can create lines of great variety.
Very few printmakers today limit their prints to one process. The many etching and engraving methods are frequently combined with excellent results.