Nowadays when I paint it's almost exclusively with egg tempera. I first read about it in a book on painting techniques from the 1930s, and later discovered the American artist Rob Vickrey. Rob’s mysterious and luminous paintings inspired me to have a go and I've been experimenting with egg tempera since the late 90s.
Egg tempera has a long history as a painting medium It was widely used in ancient Egypt for mummy paintings and there are plenty of surviving examples. It involves mixing powdered pigment with egg yolk and water to make a type of emulsion. The paint is quite translucent and dries very quickly so it can be layered into complex compositions. The paint remains soft for a while but gradually hardens into a tough film of extraordinary durability. Egg tempera protects and preserves the support that it is painted on (usually wooden panels), unlike oil paint which is acidic and causes canvas to slowly disintegrate,
The most famous egg tempera painting is probably Boticelli’s Birth of Venus from 1485 (see above). The medium was in widespread use in medieval times and the early renaissance, particularly for religious icon paintings. Many of them survive in perfect condition due to the properties of the emulsion. After about 1500, when oil paint became widely used in Europe, the popularity of egg tempera rapidly declined. There was a modest revival in the 20th century with Marc Chagall, Giorgio di Chirico, Mark Rothko and others using it in their work.
The particular characteristics of egg tempera present a number of challenges to the artist and the process can appear a bit laborious.
When I first tried it I worked on paper and cardboard but I later discovered that renaissance painters sometimes glued linen onto wooden panels to paint on, then priming them thickly with gesso (a mixture of glue and white pigment) and smoothing them down. After much trial and error with different kinds of board, linen and glue I found a combination that produces a stable support. But I prefer the colour, texture and absorbency of raw linen and usually prime it only with egg wash. This creates a versatile support which is very stable and durable.
The quick-drying quality of egg tempera paint means that, traditionally. images are built up from flat areas of colour with hatching, stippling and over-painting to create shading. However on raw linen it's possible to work wet-on-wet and to blend and shade much more naturalistically. Where more layers of paint are applied, the texture gradually becomes smoother and less absorbent. This make faces, in particular, really stand out and look uncannily three dimensional and life-like. Clothing, in portraits, also looks incredibly realistic, either retaining the natural texture of the linen, or a smoother texture where there are more layers of paint.
I've written a short guide to getting started with egg tempera painting which you can download from here:
Pete Swann guide to egg tempera