Crack Open Your Shell
How egg tempera can produce brilliant light and rich shadows

by Douglas Wiltraut

It was back in the mid ‘60’s that I found myself walking through a local
mall in my home town looking at a traveling art show from the collection of the actor Vincent Price. I can’t remember who the artist was but there was a very small painting that I was attracted to. It had a very matte, waxy look to the
finish and I remember marveling at how it didn’t matter at what angle I stood
to look at it, there wasn’t a glare off the surface unlike the varnished oil
paintings. I proceeded to look at the identification label and saw listed as
the medium the words, Egg Tempera. Soon afterwards, in 1966, my parents took me to the Andrew Wyeth exhibition at the Philadelphia Academy of Fine Arts and after waiting in a line four blocks long, the deal was sealed. These early exposures began a lifelong fascination with this medium that continues to this day.

Though in use since the early Renaissance, the practice of painting in egg
tempera has remained one that is shrouded in mystery. Each generation of
painters had their handful of egg tempera practioners. In America the names of Paul Cadmus, Thomas Hart Benton and George Tooker, to name a few, carried the torch until the popularity of Andrew Wyeth’s work over the past fifty plus years elevated the medium back into the public limelight. There was a time when the only available written material on the subject was Daniel V. Thompson Jr.’s the Practice of Tempera Painting, a paraphrased translation of the original work of Cennini, but now books by the likes of Robert Vickrey, another of America’s foremost egg tempera painters, and access to the Internet have begun to uncloak the mystery that has kept this remarkable medium in relative obscurity.

Painted on a panel sized with rabbit skin glue and gessoed with true gesso,
egg tempera is capable of effects that continue to fascinate even those most
familiar with the medium. I paint on quarter inch panels of standard Masonite
which receive, after two separate coats of rabbit-skin glue sizing, five coats
of gesso to the front side of the panel but six coats to the back side. This
is done to maintain equilibrium to the panel by allowing the moisture from
the paint layers to equal the sixth coat of gesso. The gesso on the front side
of the panel is then smoothed by rubbing a small block of wood that has been dipped into clean water in a circular motion on the gesso until the block
begins to stick and then remoistened. This method can produce a panel that is pure white and as smooth as ivory.

While often used in an opaque manner, I have found that some of the most
luminous effects can be achieved by trying to keep all of my colors transparent. By building up thin transparent layers of pigments until the desired value and color are achieved, light is able to pass through this buildup of thinly layered colors, strike the white gesso and reflect back through the thin glazes of multiple colors creating the appearance of an inner luminosity. It is between these layers where the artist can introduce details or textures using opaque colors at various stages of the development of the paint surface. By glazing more transparent colors over top of these opaque inclusions, they can appear suspended or trapped within the atmosphere of a shadow. Spattering different sized dots or flecks of paint, some opaque, some transparent, is an effective method to use in depicting the texture of rock, brick, concrete, rust, dust, wood or just dirt on the ground. These spherical balls of opaque paint locked in, floating if you will, between layers and layers of transparent paint create an endless array of textures. The possibilities are limited only by the amount of time and experimentation the artist is willing to invest.

A medium that has long carried the stigma of being difficult to master
because the artist had to “make his own paint”, egg tempera is really just a
simple combination of pure egg yolk, distilled water and dry pigment. I say dry pigment here because many tempera painters will premix their pigments with water into a paste that they store in lidded jars but I have always preferred to have the dry colors right on my palette. The egg yolk is separated from the white of the egg either by passing the yolk from palm to palm or using an egg separator. I prefer to use my hands and I alternately wipe off the excess egg white with paper towels. Just as paper can inflict a nasty paper cut, in this case you have to be careful not to cut the yolk with the edge of the paper towel. Once the yolk sac attains a leathery matte look I pick up the sac between my thumb and index finger, hold it over a small dish and puncture the sac. To this I add an equal amount of water which usually is about a tablespoon and a half. This mixture is what is added to the dry pigment. There is a direct correlation between the size of a brush, how much egg medium it can hold and how much dry color sticks to the brush. Somehow this equation holds true when the test of scraping the dried mixture from the glass palette with a razor knife blade to see if it is properly mixed produces beautiful waxy curls of paint not unlike those produced when a crayon is sharpened in a pencil sharpener. Simply put, if, in performing this test, the color bunches up and is mushy there is too much egg and if the paint flakes off there is not enough egg. After the color is mixed properly it can be further thinned with water but it is at this point where many artists will experience their first difficulties. To produce these previously mentioned glazes, almost all of the paint should be squeezed from the brush in classic drybrush style. This avoids the most common pitfall that can occur whereby a brush with too much moisture can and will dislodge colors already applied. This can also be detected if after a thin brushstroke is applied there is a tell-tale drop of moisture at the end of the stroke that will take the form of a darker droplet of color.

Although I mostly use round kolinsky sable brushes, I’ve found that the brush
is most effective when the sandpaper-like finish of the panel wears the tip
off the brush and it has more of a blunt appearance. When squeezed of its
moisture a brush of this shape is perfect for applying thin,dry glazes. The
argument can be made for using a synthetic sable because it can withstand the “grind” of the surface and is more economical. For creating textures, a brush with good “snap” is most effective in producing spattering effects. Traditionally round sable brushes have been used to execute cross-hatched patterns of paint application, however, modern painters using egg tempera have used rags, paper towels, toothbrushes or any other means to apply the paint. The door to experimentation remains wide open with this wonderful ancient medium to all who share the same passion for depicting the effects of light and shadow, time of day and atmosphere.