Among the Material Library's bounty of curiosities are samples of cochineal, a gloriously red pigment developed thousands of years ago by the Mesoamericans. They discovered that pinching an insect found on prickly pear cacti yielded a blood-red stain on fingers and fabric. The parasitic scale insect, known as cochineal, was transformed into a precious commodity. Breeders in Mexico’s southern highlands began cultivating cochineal, selecting for both quality and color over many generations. When the Spanish conquistadors landed in Mexico, they were struck by the stunning scarlet colored textiles, furs, baskets, feathers, and ceramics of the New World. The Spanish would go on to ship tons of the dried insects back to the Old World and beyond. Their monopoly on the color's source made it one of their most valuable exports from Mexico, second only to silver. (Click here for a more detailed history.)
When the pigment reached Europe, it was used largely for dying textiles. However, artists would often re-purpose the pigment from old textiles and those that could afford the dried insects would combine them with a binder rendering a version of cochineal called lake. Despite its bold, glorious color, the dye or paint faded in a matter of a few years. By the late 20th century, artists had abandoned cochineal.
The left-hand image of Renoir’s “Madame Léon Clapisson,” (1883) hangs in the Art Institute of Chicago. A team from the AIC and Northwestern used a high-power microscope and X-rays to examine the cochineal pigment particles and then digitally recreated the portrait (and cochineal) as it was first painted.