Monday, May 28, 2018

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)