Ancient Medium - Egg Tempera Painting, Part 3 - Preparing the Egg and Pigments

Part 3 – Preparing the Egg and Pigments

Painting with the yolk of an egg means that the yolk is the binder in the pigment (as linseed oil would be the binder in pigment for oil paint) and then mixed with raw pigment and applied to a rigid surface prepared with gesso. There are other forms of emulsion, but egg and water is the most common. As with baking the egg yolk is separated from the white. Painters get in the habit of having lots of meringues, nougat, soufflés and egg white omelets!  Once separated the yolk is gently dried off a bit by rolling it back and forth very gently in your hands or on a paper towel (gently can’t be emphasized enough) so that the yolk can be either slightly wrapped in the palm of your hand or pinched very gently while held over a jar and pierced with a knife or a pin.  The yolk that spills out into the jar is used for painting.  What remains is the yolk sack that can be discarded but should not be allowed to fall into the jar.

Painters use varying ratios of yolk to water.   A common is ratio is 50:50.  If you have potable well water it can be used straight from the tap; if you are on city water best to use bottled distilled water due to additives.

The prepared egg can be used for a day, possibly two at the most if it was really fresh, before discarding it.  Generally most, if not all, of the egg will have already been used in the process of painting thereby producing no waste. 

Working With Raw Pigments

The pigments used in egg tempera painting are the same ones used for other mediums (such as watercolor, oil, gouache). Manufacturers find pigments all around the globe.  There are ore, mineral, plant, oils and insect based, as well as stone, resin and synthetic based (chemically made such as cadmiums).

It should be said that working with raw pigments carries different degrees of risk.  Many of the pigments in their raw or dry state can be toxic. Even more benign pigments, such as earth colors, can harm the lungs if inhaled because of the high silica content.  Take precautions and then enjoy the vast array of colors!

When working with all raw pigments in their dry state a respirator should be used.  This eliminates the problem of worrying about their level of toxicity (refer to Robert Mayer’s The Artist’s Handbook for information on the chemistry of pigments).  It helps to keep small jars of each pigment you use and to turn each color into a paste.  Wearing the respirator put enough into each jar to almost fill the jar.  Add water and stir.  This creates a paste that will probably dry in the jar depending on how much and how often you replenish the colors you use.  Topping off the jar with a thin layer of water keeps the paste from drying out. This way you’ll have each hue you want to work with ready when you are without having to work in the dry state at the start of each painting.

When you’re ready to use a pigment take a very small amount out (perhaps one-eighth of a teaspoon – you’ll learn how much you generally need of each color) and place on your glass palette.  Glass is used as you’ll need to temper, or grind, this pigment to mix with the egg.

Using an eye-dropper add about as much yolk as you have paste (again, you’ll get used to the proportions that work for you).  Then using a palette knife work the mixture with a motion similar to spreading butter on toast, moving the knife back and forth to combine the ingredients while you also grind the pigment and yolk mixture on the glass. The paint is then ready for applying to the panel.  This takes practice.

Next Up, Part 4 - Applying the Pigment (on June 4)

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)