We all know how frustrating it is to scrape egg off the breakfast dishes, not to mention off the side of the house at Halloween time, if we have been so blessed. Nothing sticks quite like egg yolk.

Early Italian Renaissance artists discovered making paint with egg yolk and water, which yields the remarkably tenacious medium: egg tempera. It is startling to realize that the humble egg is the basis of some of the masterpieces of Western art. Paintings such as Botticelli's Primavera were produced with this beguiling medium.

Let's dispense with something right away. It is temp-ER-a, not temp-UR-a. The first is paint, the second is a type of Japanese cooking. There is still another area of confusion regarding egg tempera. In general use, many people refer to low-grade poster paint as "tempera." True tempera however is egg tempera first used centuries ago. "Tempera" comes from tempering the paint, that is, grinding dry powdered pigments into a mix of egg yolk and water to make a runny paint.

Both simple and complex in mixture, easy and difficult to use, egg tempera is one of the least understood media available to painters. It dominated easel painting in the Renaissance from the making of portable altarpiece paintings in the thirteenth century onward to its golden age of religious paintings and secular portraits in the fifteenth century. It is a medium full of virtues and vices that delight or confound any artist who has attempted to work with it. Most modern painters never try it, mainly because it is not commercially available and because it is one of the more daunting media in its making and handling, which requires considerable time and craftsmanship. For any artist of a fast-food mindset, forget egg tempera. When done properly, it requires the artist to do everything from scratch—from making the necessary panels by hand, to making the paint, to making time for lavishing hours and hours on images.

If you were Sandro Botticelli or Fra Angelico, living and working in Florence in the quattrocento (fifteenth century), you understood the demands of the medium and welcomed them. Those artists produced some of the most colorfully luminous and highly detailed paintings that have survived from that period. Their works have aged gracefully. The colors of egg tempera paintings done by Botticelli and Angelico typically have remained remarkably stable and bright, seemingly as fresh today as when the paint dried on them four centuries ago. Contrast this to oil paintings, which often darken with the passing of the decades due to the linseed oil in their mixture. Consider also that oil paintings on canvas are typically prone to large scale cracking in the paint surface. As the weather changes the usual canvas support does not expand or contract at the same rate as the oil paint on their surfaces, hence large cracks.

So why has oil painting eclipsed egg tempera as most painters' medium of choice since oil first appeared in the 1400s in Europe? The answer is simple: oils dry slowly and are easier to blend. Egg tempera dries extremely fast; strokes of color set up within about three seconds. This means that gradual blends of color and tone in a tempera must be done with countless tiny brushstrokes, which give the illusion from a certain viewing distance that one is gazing at a smoothly blended surface. Not many artists have the patience to develop a passage in a work where it might require hours of detailing and glazing to finish a few square inches.

There are a few American artists in the postwar period who have practiced egg tempera in the United States and have done some amazing and profound works with the process. Most notably they include Andrew Wyeth, Robert Vickery, and George Tooker. Wyeth, whose works such as Christina's World and Wind from the Sea (along with his Helga paintings) has become something of a household word.

Because of lack of education available in this medium, most American artists have had to go it alone in the learning process. In recent times there have been a few practical guides to the practice of tempera painting. The most useful is Robert Vickery's New Techniques in Egg Tempera, published in 1973. Also in Mark Gottsegen's A Manual of Painting Materials and Techniques the aspiring painter can find a very worthwhile chapter on how to make and use the medium. Veteran artists might also be familiar with Ralph Mayer's The Artist's Handbook of Materials and Techniques which is quite helpful. As these books became available they offered excellent help to artists struggling to gain mastery of the medium.

Let's try to put the process into an eggshell description. Its challenges are two-fold: First a painter must make a rigid panel for the permanent support of the painting. Second, he must make the paint from scratch and use each batch for a few days before discarding it and mixing some more.

Panels are best made using Standard Masonite which must be braced with hardwood strips glued on the back for paintings larger than 30" by 36", then the panel is coated with a sizing of rabbitskin glue. Next, traditional gesso must be obtained, not the acrylic product sold as "gesso" in countless art supply stores. Real gesso is a mix of rabbitskin glue, powdered chalk and white pigment. It must be mixed with water and heated in a double boiler until it becomes the consistency of heavy cream. This is applied in layers to the sized panel with an equal number of coats (front and back) to minimize warping. When the panel is dry and hardened, it must be sanded smooth. This requires increasingly finer grit sandpaper, finishing sometimes with a 400-grit emery paper to achieve and ivory smooth surface. It can take more than ten hours just to prepare a modest sized panel before one stroke of color can be applied.

Drawing of the images can be done directly with pencil on the panel or the initial contour drawing laid in with a fine brush and a little paint. As for the paint itself, one obtains a variety of fine-quality dry powdered pigments. When tempering a color, it takes about a tablespoon of powder placed onto a heavy piece of glass. The egg medium is half egg yolk, half water. In the Renaissance, Cenino Cennini, who wrote a book about painting, advised that one should use eggs from city chickens rather than country chickens, since the former were more likely to be paler and less likely to influence the color of the paint, but actually the yellow of the egg does not prevent whites and intense blue hues from being produced.

A little of the egg medium is then poured onto the pigment and ground together with a broad palette knife, scooping it into a shallow porcelain dish when mixed well. The same is done for each of the colors employed in the artist's palette. It can take almost an hour just to mix a batch of paint before sitting down with it before the easel. No one has found a way to extend the life of this paint. Since the paint dries so fast, it becomes excellent for attaining fine line details for which the medium is best known. Anyone who has marveled at the strands of hair in a Wyeth portrait or the tawny grasses in his landscapes knows what is meant here. Beyond the layering of textures one can achieve in this medium, the viewer may be charmed by the semi-mat surface of the painting. Furthermore, the painting seems to possess an inner glow, the effect of the brilliant white panel showing through the paint layers, which tend to be semi-transparent.

Egg temperas tend to be high-key in tone, with the darks difficult to develop with the depth and richness of oil. Nevertheless in the middle value and upper tonal range it possesses a subtlety of surface and texture which are unmatched. It tends to be a crisp, uncompromising medium best suited for the draftsman.

No where is this more evident than in Botticelli's La Primavera, which is unusually large as temperas, go. It measures almost seven feet in height by over ten feet in length and is one of the gems of the Ufizzi Gallery in Florence, Italy. Scholars cannot agree on when Botticelli produced it. The suggested dates swing between the mid-1470s to the early 1480s. Botticelli produced it on a panel made of many edge-glued pieces of poplar wood cross-braced to stabilize it. Its composition seems deliberately cryptic, dominated by the central figure identified as Venus, who raises her right hand in a gesture of benediction. The setting is a grove of orange trees above a lawn carpeted with many species of plants in full bloom.

Countless viewers have been enchanted by the Three Graces on the left of the picture. Dancing in slow movement, they are one of the most memorable trios in art history. Quite different in pose, they nevertheless enjoy a kinship with the three marble goddesses from the west pediment of the Parthenon. What they have in common is the lyrical presentation of three females whose voluptuous figures are more revealed than concealed by the flow of drapery around them. In his painting Botticelli achieved an unmatched illusion of diaphanous gowns which ripple around the figures in a ballet rhythm of line and transparent tones. Looking closely at the passages of painting in this or any other egg tempera painting, the viewer sees that the paint is not built up with any thickness. It must be kept quite thin and smooth for best adhesion. It cannot be laid on with a thick impasto like oil paint. Thick applications of egg tempera will crack severely and even flake off the panel. Knowing this, Botticelli imparted an almost enamel-smoothness to his paint.

Looking closely at the any of the faces in his figures one notices the delicate crosshatching of tiny strokes which Botticelli used to model his forms. Nothing is ambiguous in outline, no surface left patchy, or unrefined.

Therein lies some of the essence, the beauty, of his work. There are no stray brush strokes, no impulsive gestures. All is astonishing, almost reverential craft, as the ideas he contemplated were translated into visual forms. His work seems the very antithesis of an abstract expressionist artist; Botticelli must have worked on this painting steadily for no less than a year.

Egg tempera hovers uniquely between watercolor and oil. It can be handled thinly with much water for the transparency of watercolor and exploit the brilliance of the panel beneath. Also, it can be applied coat after coat of the paint, stroke after stroke, watery glaze after glaze until passages are achieved that have the density of oil.

In my tempera portrait, "Syumuka" (front cover) there was the challenge to render the likeness of my model who was graced with flawless features. Endless hours were spent layering the fine crosshatching that modeled the shadows of her face, arms, and hands. The rich mahogany of her skin required a great deal of additional stippling and glazing to achieve her glowing, sculptural effect. Painting her dress proved equally challenging. Before the color patterns could be applied, the 'anatomy' of the folds had to be developed in light and shade. If the artist fails to observe value structure as the primary goal, bold patterns can flatten out form. Figure and costume came together in an image of delicate poise.

One thing about tempera is that whatever difficulty a painter may be experiencing in a passage, new layers can be built over it to submerge the problem. This layering approach usually can lead to quite a feeling of density and weight in the image. If disastrous trouble arises in a section, the final resort is to scrap off the paint with a razor blade, re-sand the area, and start over.

When we examine Wyeth's painting, "The Patriot," we can only wonder how many corrections, adjustments, fresh observations, accumulated in his portrait of the aging World War I veteran. The egg tempera medium allowed him to react quickly to changes in the image as he made new discoveries both about the appearance of the man and his own feelings about the subject.

Quite unlike Wyeth in temperament, George Tooker used tempera to create one of the most chilling images in mid-twentieth century painting. "Government Bureau" is a surreal, yet superbly rendered image of a soulless bureaucracy and the depersonalized humans who dumbly submit to the endlessly replicated cubicles and agents. Tooker seems to belong to a cadre of post-war New York artists with a strong streak of social commentary in their work, including Paul Cadmus and Jared French. Tim Lowly is a Midwestern painter who has created unique, symbolic paintings of interiors, landscapes, and his handicapped daughter.

Around the nation there are a handful, (but growing) number of painters who have turned to egg tempera for the challenges of its special beauty. Its difficulties often challenge an artist to probe deeply into his intentions for a picture as it takes shape. In most cases it becomes a marathon, but it offers the satisfactions of a sustained artistic campaign. Working in comparative isolation, egg tempera artists nevertheless find that the discipline sets them apart. Good painters in oil or watercolor are plentiful, but egg tempera painters are a rare breed experiencing the rich alternatives of this time-honored medium. They avoid virtuoso performances with the brush and offer images which are often contemplative, yet infused with a passionate feeling for an image and for the medium which enables its creation.