Limewood panel bearing portrait in encaustic and tempera of naked young man with curly hair, 80-120. Courtesy of the British Museum.
Oak panel bearing tempera portrait of a bearded man wearing a white tunic with purple clavi, 2ndC(early) Roman Period. Courtesy of the British Museum.
In the refrigerator, fresh eggs can keep for three weeks. But mixed with color pigments and painted onto a wood panel, they can last close to 2,000 years. For evidence of the lasting power of the medium, you might not need to look further than your kitchen. “Think of egg yolks on your breakfast platter—if you don’t clean it right away, it’s quite difficult to get those residues off your plate,” says Dianne Modestini, a professor at NYU’s Institute of Fine Arts and a conservation specialist in Old Master and 19th-century paintings, who restored Leonardo da Vinci’s Salvator Mundi (1490).
The use of eggs as an art material has stuck throughout the history of art, though it’s unclear who first dabbed paint brushes in their viscous, yellow-whiteness. Some credit the ancient Egyptians, after the discovery that some Fayum mummy portraits from the first few centuries A.D. include egg. Others think painting with egg was a Greco-Roman technique first, since it was mentioned in texts by the ancient Romans Vitruvius and Pliny.
But regardless of who initially invented creative uses for the humble egg outside the culinary arena, it soon became a staple of many an artist’s studio. Egg yolks were mixed with color pigments in a technique called egg tempera, which was the prevailing medium for early Italian Renaissance panel paintings and one frequently used by artists such as Fra Angelico, Domenico Ghirlandaio, and Andrea del Verrocchio.
Fra Angelico, The Forerunners of Christ with Saints and Martyrs: Inner Right Predella Panel, 1423-4. Image via The National Gallery, London.
Cennino Cennini, a Quattrocento painter trained by students of Giotto (the artist heralded as the father of the Renaissance) is the earliest-known publisher of an egg tempera formula in his craftsman’s manual, Il Libro dell’Arte o Trattato della Pittura (The Book of the Art of Cennino Cennini). “You must temper your colors always with yolk of egg,” Cennini instructed, “[and] always as much yolk as of the colors which you temper with it.”
Hundreds of years later, yolks were discarded in favor of egg whites, which were frothed with salt and used to coat paper for mid-19th-century albumen photographic prints. “At that time, everything [in photography] relied on kitchen chemistry,” says Art Kaplan, a photography conservation scientist at the Getty Conservation Institute. “It was people at home, working and trying out different things.”
After the albumen process was publicized by French photographer Louis Désiré Blanquart-Evrard in 1850, albumen prints became one of the most prevalent photographic processes of the 19th century and were used to print images by photographers from Gustave Le Gray to Roger Fenton and Félix Nadar.
Both media have produced works with a canonical and physical longevity that laughably contradicts the normally short shelf life of their base ingredient. But making art with eggs is not without its conservation risks. In many ways, it has proven to be a recipe for fragility.
Egg tempera paintings, for example, are much more vulnerable to the elements than their oil-painted counterparts, because their thin layers create a minimal protective film. “Embedded dirt, grime, and soot that’s generated by the atmosphere tends to bond to the surface because the paint film doesn’t have as much integrity [as oil paint],” explains Modestini. “In oil paint, the pigment particles kind of settle to the bottom and it forms an enamel on the surface which, as the linseed oil dries, becomes a much tougher film. In egg tempera, it doesn’t have this protective enamel of the medium, and the pigments are more exposed.”
This makes it particularly challenging to conserve egg tempera paintings, as well. Conservators must use an especially light touch, since the works are not as resistant to cleaning as oil paintings. “Egg tempera is rather vulnerable,” Modestini warns, “and one has to be much more careful not to damage the paint film.”
Albumen photographs, meanwhile, are similarly susceptible to degradation because the egg white paper coating is more permeable than processes that came into vogue later, such as gelatin. Though the process was immediately popular because it offered sharper images with greater tonality than its predecessor (the salted paper print), albumen proteins are sensitive to changes in temperature and humidity.
“They knew there were issues [with albumen prints] from the start,” Kaplan says. The prints tended to yellow more easily in the white highlight areas, and networks of fine cracks would develop within only a few years. Manufacturers tried to address these problems early on, adding citric acid to the coating as a preservative. But eventually the albumen process was abandoned in favor of the silver gelatin print, which could produce glossier images and was more durable.
They were also, Kaplan surmises, cheaper to manufacture. “You didn’t have to keep a supply of chickens on your farm to produce silver gelatin photos,” Kaplan says.
Despite its unique conservation challenges, many artworks that include egg have endured. And there are still contemporary artists choosing to work in these two media, despite the difficulty of using a highly perishable and sometimes difficult material (egg tempera was nicknamed “la pittura al putrido” in Italian because of the stench of days-old yolks).
The celebrated mid-20th-century realist painter Andrew Wyeth worked mostly in egg tempera, for example. And Koo Schadler, an artist who has painted exclusively in egg tempera for the past 25 years and is a board member of the Society of Tempera Painters, has followed Wyeth’s lead into the present day. “Egg tempera is an ideal fit for me,” she says. “Simple, elemental ingredients; requisite, sometimes demanding craftsmanship; a thin, incorporeal-like paint; methodical planning of an image; gradual, meditative accumulation of layers…all things that suit my nature and lifestyle.”
Morgan Post, a photographer and professor of photography at Long Island University who is currently working on a series of formal albumen portraits of sideshow and circus performers, is aware of the process’s conservation issues, but has incorporated them into the work. “The yellowing kind of just happens, you know,” Post says. “There’s techniques you can use to skirt that a little, but I like the yellow, honestly. It kind of fits with the aesthetic of the work I’m doing—it ages it.”
Many new media have been invented during the bimillennial art history of using eggs in art, but the potential-rich ovoids still have a creative future among those willing to get their hands sticky. There are, evidently, good reasons why egg tempera and albumen prints made their mark in the first place.