Model Sleeping, 1997
lithograph, 540 x 360 mm

Turn Off Pond, 1999
lithograph, 600 x 400mm

Lithography

Lithography is a printmaking process invented by Aloys Senefelder in 1798 which uses a press to transfer an image that was created initially on stone or metal plate to paper. Its basic principle is the natural repulsion of grease and water, so the crayons, pencils, and washes used in lithography have a high grease content.

First the artist draws an image on a fine-grained limestone or aluminum plate. For a one-colour lithograph, this will be the only drawing but each additional colour will generally require a separate stone or plate. Once the artist has finished drawing with the greasy black pigments, an artisan printer takes over and chemically treats the stones and/or plates to stabilize the image for printing.

The non-image area of the stone's surface is waterproofed and kept wet to prevent the ink from adhering to these areas. The printer then removes the original drawing materials with a solvent, leaving the greasy image barely visible on the stone. The printing inks, which are also greasy, will adhere to the image area. This is the essence of lithography. The natural opposition of oil and water.

At the press, the printer sponges the stone or plate with water, rolls it with ink, and prints a series of "trial proofs": the same image with different colour and paper combinations. When the artist is completely satisfied with the result, the final proof is signed by the artist as the bon a tirer (B.A.T.), "good to pull". With this as a standard, the printer is ready to pull the edition.

Once the edition has been printed, the stone or plate is destroyed or erased, ensuring that no more impressions can be printed. The curator checks each impression against the B.A.T., and the artist signs and numbers the impression.

Sutton, 1990
egg tempera, 720 x 505 mm

Auripo Road, 1979
egg tempera, 748 x 420 mm

Egg Tempera

Egg tempera is an ancient painting tradition which fell out of favour once oil painting was perfected in the 16th century. It is very labour-intensive compared with oils, although tempera offers wonderful results which are not duplicated by any other process.

Egg tempera paint is applied thinly and each subsequent layer is affected by the former. Every change of one tone to another has to be separately mixed, then carefully applied and modulated. This gives it a clean, matte finish and subtle colour variations which are unlike the deep saturated colors typical in oil paints.

The artist must manufacture the paints himself by mixing finely ground pigment, water and diluted egg yolk. Egg yolk forms the glutinous substance that binds pigments to the surface of the panel, but the yellowness of the egg disappears immediately as the water evaporates. This fast drying property makes it best suited for a more linear style rather than the thick, brushy and painterly technique of oil painting.

Although tempera dries to the touch in a few seconds, the paint does not fully cure for up to nearly a year. The fragile surface of the painting needs protection from scratching or water damage for the first year.