The Etching Process

The Etching Process

The Etching Process

In etching, an image is drawn onto a metal plate (copper or zinc – I use zinc) which has been painted with a thin, acid-resistant layer of bitumen, called a ground. The image, which is drawn on the ground with a metal stylus, removes the ground, and when the finished plate is submerged in a solution of nitric acid, the exposed zinc is dissolved, or bitten, creating a series of fine lines that are the reverse of the image drawn through the ground.

The depth of the bite depends on the time the plate has been in the acid. To add to the etching, or change it, the plate can be re-grounded and re-bitten as many times as required.

When the plate is completed, its surface is inked then wiped clean and the plate is placed in the etching press on a sheet of moistened archival paper. The pressure of the press roller transfers the ink remaining in the bitten lines onto the paper, creating a print. For each print, the plate is re-inked. The prints in each edition are almost identical, though minor variation in tone can occur.

Editioning

Traditionally, only a limited number of prints are made from a plate, after which the plate is drilled or scored so it can no longer be used. The prints made from a plate are called an edition. The edition number written under a print is in two parts – the first number is the individual print number and the second is the total number of prints in the edition. 

Some prints may be labelled A.P, meaning an artist's proof copy. 

An edition of hand-coloured prints is labelled variable to indicate that the individual prints may vary in colour.