Glossary

• Aquatint

  An intaglio printmaking process and a method of achieving tone by etching a plate covered with resin dust. The acid corrodes the unprotected metal leaving only the surface protected by a speck of dust. When inked the plate will print a tone of black through to very pale grey depending on the length of time it was immersed in the acid. Its name derives from the finished print resembling a watercolour, and is a tonal rather than a linear work.

• Drypoint

  An intaglio printing process where the lines are scored directly into the plate with a sharp needle, which can be used much like a pen. The line leaves a deposit of metal in its wake known as a burr, which when printed holds a small deposit of ink and gives the drypoint line a characteristic softness of tone. Its disadvantage is that such plates wear out quickly, so editions are usually limited to 50 or fewer prints. Drypoint is often combined with other printing techniques.

• Edition

  All copies of a book, print, portfolio, sculpture, etc., issued or produced at one time or from a single set of type. Printed works can be made in an edition of between one and many thousands of copies. With most printing techniques the plate or screen will become worn if very many prints are made, so to maintain quality (and exclusivity) editions of original prints are usually kept below one hundred copies and normally average between thirty and fifty copies. Prints made up of several different plates can be extremely complicated and time-consuming to edition, so in these cases editions are kept low for practical reasons. Sculptural editions are a set of cast sculptures taken from the same mould or master. These editions are usually much lower, consisting of no more than six casts. Though each cast in an edition might have a lower value than a unique piece, it may be a more effective way of offsetting costs of an expensive process such as bronze casting.

• Etching

  An intaglio process whereby a metal plate (normally copper, zinc or steel) is covered with an acid-resistant layer of rosin mixed with wax. With a sharp point, the artist draws through this ground to reveal the plate beneath. The plate is then placed in an acid bath (a water and acid solution) and the acid bites into the metal plate where the drawn lines have exposed it. The waxy ground is cleaned off and the plate is covered in ink and then wiped clean, so that ink is retained only in the etched lines. The plate can then be printed through an etching press. The strength of the etched lines depends on the length of time the plate is left in the acid bath.

• Lithography

  Lithography means, literally, stone drawing. In addition to fine grain lithographic stones, metal plates can also be used for lithography. The method relies on the fact that grease repels water. An image is drawn in a greasy medium onto the stone or plate, which is then dampened with water. Greasy printing ink rolled onto that surface will adhere to the design but be repelled by the damp area. The inked image is transferred to the paper via a press. For large editions, the grease is chemically fixed to the stone, and gum arabic, which repels any further grease marks but does not repel water, is applied to the rest of the surface. For colour lithography the artist uses a separate stone or plate for each colour required.

• Negative

  An image in which colours and shades of an inage are reversed: the light areas of the object appear dark and the dark areas appear light. Also refers to a film, plate, or other photographic material containing such an image.