In other works food has been incorporated in less-obvious ways. For centuries egg yolk has been a key medium for paint, helping the pigment adhere to the painting’s surface and keeping the color stable, explained Ruby Awburn, Richard I. Shader Fellow in Paintings Conservation at the museums’ Straus Center for Conservation and Technical Studies. “Egg tempera, not to be confused with the tasty Japanese dish egg tempura,” was a traditional means of stabilizing a pigment that had been first mixed with water to make a paste, she said. By combining the colored paste with yolk, painters could apply the hue to their work and ensure it would stay put. As the egg dried, it hardened into a film, locking the color in place.
But the product had its drawbacks. “Egg tempera is not a flexible medium and requires a stiff support,” rendering the use of canvas impractical, said Awburn. In addition, it dries quickly, meaning colors can’t be mixed together directly on a work’s surface, as is the case with oil-based paints. And because the egg medium can only carry a small amount of pigment with each stroke, it requires repeated applications to build up color.
Still, artists are nothing if not inventive. To create the fine details on their egg-based works, artists would use “small, linear, single-stroke brushwork,” said Awburn, creating “highlights and shadows with light lines and crosshatching.” Such techniques can be seen in the museums’ 1490 work “The Virgin and Child” by Botticelli, said Awburn, noting that a close examination of the Virgin’s face reveals the “crosshatching in her skin-tone variations.”
Despite the evolution of new paint formulas, contemporary artists continue to embrace earlier materials and techniques, sometimes with a modern twist. A case in point is American painter and Harlem Renaissance prodigy Jacob Lawrence and his 1951 work “Ventriloquist.” While he “embraced the semi-transparent wash that egg tempera provides,” said Awburn, instead of using small strokes and crosshatching to flush out the details, he opted for “flat washes of color with deliberate visual brush strokes emphasizing and supporting his cubist and illustrative style.”