Ancient Medium - Egg Tempera Painting Part 2 - The Process

Part 2 – The Process

Egg tempera painting is a long process, both in preparation ahead and development of the painting later.  It is also a very meditative and mindful process.  This blog is not meant to be a how-to of egg tempera painting (there is too much for that and excellent instructors dedicated to teaching the medium), but instead information about this very special ancient medium for people who are interested.  

Egg tempera paintings are durable, can be very luminous, and have a soft finish in the end that is somewhere between microfiber and silk with a hint of wax. This means the value of a truly good egg tempera painting is well worth the price once you understand what the artist has gone through to create it.  

The process also gives today’s artist something they can no longer have – the sense they are working in the pre-Renaissance of Cimabue and Giotto, with the Old Masters of Italy in the crossover period to oils of the 13^th to 14^th centuries (Vermeer, Campin), by the time of the Renaissance painters of the 15^th century (Botticelli, daVinci, Bellini, della Francesca) oil as taken over as the medium of choice. There was a revival in the 20^th century use of egg tempera through artists like Ben Shahn, Andrew Wyeth, Lucian Freud, and Isabel Bishop.

The process also gives the artist a sense of being an alchemist in the ancient tradition.  Oil painters can also make their own paints, but less likely as so many varieties are readily available to use straight from the tube.  The range of pigments available to egg tempera painters in raw form (same as those for oil) come from all around the globe from natural sources (minerals and earth) and synthetic.  It is up to the painter to learn the chemistry of the various pigments, what will work well and what won’t, the toxicity of the pigments, and to mix and use them effectively.

Substrate

Egg tempera paint must be applied to a rigid, smooth surface otherwise it will crack once the yolk dries.  Therefore panels, not stretched canvas, are used.  Panels are usually made of wood although metal has been used.  If an organic surface such as wood is used it must be a type that is stable such as birch (other types may be used such as cabinet grade or marine grade plywood, but prepared panels may also be purchased).  Fabric such as canvas or linen can be used once it is glued to the panel.  The wood surface (and fabric if applied) must first be sized to help prevent any future warping due to humidity or dryness.  A size of animal hide glue is generally prepared and applied to both sides and all edges of the panel.  Once the size dries, layers of gesso are applied.

Gesso

Similar to oil paintings that are painted on canvas or linen, the substrate is further protected with a substance called gesso.  Egg tempera panels must also have gesso mixed by a specific recipe and applied in a specific manner.   Acrylic gesso is used for oil painting, but most egg tempera painters use a traditional recipe similar to that thought to be derived from Cennino Cennini (Florence, Italy) around the turn of the 15^th  century.  Gesso (from the Italian “gypsum” or “chalk”) is combined with size and then a mixture of plaster of paris (or gypsum) chalk or marble dust.  The first coarse, unslaked layer of gesso is then followed by about 8-15 layers of gesso.  These dry very quickly and each subsequent layer is brushed on alternating in direction.  Once completely dry the gesso is then gently sanded with very fine sand paper until the surface is completely smooth.  The first sanding is performed wet.  Taking a piece of 1500-2000 grit sand paper run under the tap the surface is gently sanded in a circular motion.  Once that dries furthering sanding is accomplished dry until the desired surface is achieved. This final opaque, white surface is highly absorbent and reflective.  Prior to actually applying paint the gesso is cleaned with denatured alcohol to removed oils from fingers or any other impurities. 

Next Up, Part 3 - Preparing the Egg (on May 28)