Lithography and Egg Tempera


Invented in the late 18th century, by the German, Senefelder, lithography is a printmaking process which uses a press to transfer an image that was created initially on limestone (‘lithos’ is the Greek word for stone and ‘graph’ is drawing).  In the 20th Century, some printers and artists began replacing stone with metal plates.

The basic principle of lithography is the mutual repulsion of oil and water. The image is drawn on the surface of the stone with a greasy wax crayon. For a one colour lithograph, this will be the only drawing. However if more than one colour is used, each additional colour will require a separate stone. Once the artist has finished drawing, a craftsman printer takes over and chemically treats the surface to stabilize the image. The non-image area of the surface is waterproofed with gum arabic and kept wet to prevent the ink from adhering to these areas. The printer then removes the black original drawing materials with a solvent, leaving the greasy image barely visible on the stone. When rolled up the printing inks, which are also greasy, will adhere to the drawn image. The ink will not stick to the wet, non-drawn areas. 

At the press, the printer prints a series of ‘trial proofs’: the same image with different colour and paper combinations. When the artist is completely satisfied the lithographs are editioned.

Once the edition has been printed, the stone is ground away ensuring that no more impressions can be printed, and other artists can go on to use the same stone to create other artworks.

Egg Tempera

Egg tempera is a water-based painting process that uses egg yolk to bind pigments to a surface. The artist produces the paint by mixing finely ground pigment, water and diluted egg yolk.

Although an ancient painting tradition, it fell out of favour when oil painting was perfected in the 16th century. However, the process, which is labour intensive compared with oils, offers wonderful results which can’t be achieved by other mediums.

Traditionally, egg tempera  is painted onto wooden panels which have been coated with multiple layers of gesso (a mixture of rabbit skin glue and whiting).  The paint is applied thinly with small sable brushes. Every tone of colour has to be separately mixed, then applied and modulated in a cross-hatch technique. This gives it a satin finish and subtle colour variations which are unlike the deep saturated colours typical in oil paints. 

It takes up to a year for the paint to fully cure.