The Etching Technique

Etching is a form of intaglio printing. This means that the ink is taken from the engraved areas of the printing plate rather than the surface areas, as in relief printing such a lino cuts. Acid is used to etch into and thus engrave a plate of copper.

The process begins with a polished and bevelled plate of copper. The copper can be protected from the acid by varnish or a wax/bitumen "ground". By removing the wax covering with a needle point, fine lines of copper can become exposed and ready to be etched. The plate is then placed in an acid bath. There are ways of varying the depth of the etched line to create distance and subtlety. When the wax ground is removed, the etching should be clearly visible on the plate of copper.

An oil based ink is then be forced into these lines and the surface of the plate cleaned off. In this condition the plate will be laid on the bed of the etching press, and damp paper placed over the top. The extreme pressure of the press forces the paper into the plate thus picking up the ink. Therefore the paper is both printed and embossed. The plate line should be clearly visible on all etchings.

Tone and colour can be added to an etching by the use of "aquatint". This is a fine powder that is dusted onto a clean plate of copper and, which when heated will stick firmly to the plate. When placed in the acid bath, the acid eats into the copper between the fine grains of rosin powder. This, too, can be varied by protecting the tonal areas at different stages with acid resistant varnish. When the rosin powder is removed with metholated spirits, the ink is pushed into the etched surface.

None of the etchings on display have been hand-tinted or painted. All the effects are the product of the acid and the press. In fact, if observed closely, the fine dots can be seen within the tonal or coloured areas.

Those etchings that have more than one colour are made with two or more copper plates, printed one after the other. Each etching is limited to an edition of prints as indicated on the picture.