Etching is a printmaking technique that uses chemical action to produce incised lines in a metal printing plate which then hold the applied ink and form the image.
The plate, traditionally copper but now usually zinc, is prepared with an acid-resistant ground. Lines are drawn through the ground, exposing the metal. The plate is then immersed in acid and the exposed metal is ‘bitten’, producing incised lines. Stronger acid and longer exposure produce more deeply bitten lines. The resist is removed and ink applied to the sunken lines, but wiped from the surface. The plate is then placed against paper and passed through an printing press with great pressure to transfer the ink from the recessed lines. Sometimes ink may be left on the plate surface to provide a background tone.
An original etching print is by definition limited edition, since the printing medium – the plate or block used to make the print – simply wears away after a number of uses. Eventually the image will have faded so much that fine details can no longer print well. After the full edition is printed, the block, plate or stone is defaced in some way so that no more prints can be taken.
In recent years a large number of artists have contributed to a major revival of the etching technique, discovering that its intricate processes and delicate lines are perfectly suited to their personal, introspective approaches to art making.