What is an etching?

Etching is a method of printing whereby a design is hand drawn with a needle through a layer of hard wax which covers a zinc or copper plate.  The plate is then immersed in a 10% acid solution.  Nitric acid being used for zinc, and ferric chloride for copper. The wax protects the surface of the plate everywhere except where it has been exposed by the needle point.  The longer the plate remains in the acid bath, the deeper the groove becomes, thus holding more ink, and give a darker image.

After the acid has etched the design the wax is cleaned off, and the plate is ready for printing. The whole plate is covered with printing ink, and then wiped clean with a gauze cloth called scrim.  This has the effect of forcing the ink into the lines drawn with the needle. Dampened paper, usually a heavy paper (300 grams) is placed over the plate between two layers of blank newsprint, padded with three wool blankets of varying thickness.  The whole ‘sandwich’ is then run under great pressure through the etching press.

Tone can be added to the image using a process called aquatint.  Grains of a special resin are fused to the plate by heating it, producing a very fine dotted texture. The longer the plate is left in the acid the darker the tone will be.  Areas can be stopped out with varnish at different stages in order to vary the tone.

A limited edition of varying quantity is then produced by the artist/printer (in Stella’s case seldom more than 100). When the edition has reached it’s limit the plate is destroyed by defacing it so that no more prints can be taken.  It usually involves drilling a hole through the centre of the plate.

What is drypoint?

Drypoint is like etching, but without the acid.  With a needle you can scratch into any smooth surface, such as copper, aluminium, or even Perspex, and the resulting line will hold sufficient ink to produce an image.  After a number of prints have been taken, however, the pressure of the press destroys the quality of the line.