Glossary

• 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.

• Glaze

  Vitreous coatings applied to pottery to make objects watertight and as a form of decoration. Also a glaze can be a thin, translucent or transparent coating applied to the surface of a painting to modify the colour tones. Glazes may also be applied on top of one another as a means of creating a sense of depth and translucency.

• Oil

  A medium in which ground pigments are mixed to produce a paste or liquid that can be applied to a surface by a brush or other tool; the most common oil used by artists is linseed, this can be thinned with turpentine spirit to produce a thinner and more fluid paint. The oil dries with a hard film, and the brightness of the colour is protected. Oil paints are usually opaque and traditionally used on canvas.

• Painting

  Work of art made with paint on a surface. Often the surface, also called a support, is a tightly stretched piece of canvas, paper or a wooden panel. Painting involves a wide range of techniques and materials, along with the artist's intellectual concerns effecting the content of a work.