Recent research at the National Gallery of Art in Washington, DC may be uncovering an untold story about a painting housed in the museum.
Conservation scientists at the National Gallery work to protect and restore invaluable pieces from around the world. However, as organic chemist Dr. Suzanne Quillen Lomax reveals, the restoration process involves quite a bit of detective work. Her work specializes in revealing the effects of time by analyzing the various materials found in paintings. Determining the materials used in the paintings can confirm their period of origin , the best methods of preservation, and what the painting may have originally looked like.
The aging process takes quite a toll on paintings, especially because many pigments used are based in organic oils that degrade and even disappear over time. But a recent study of a 15th century painting by Giovanni Ambrogio de Predis shows that the aging process may actually change the color of the works entirely. Looking at the painting today, the viewer can still see all the intricate details of the subject’s dress and jewels. During the study of the painting, the brown pigment found in the dress was analyzed using X-ray fluorescence spectroscopy. The analysis showed a large amount of copper in the pigment, which ultimately indicated the pigment was copper resinate. During the 15th century, many artists used a copper resinate pigment to add a glaze to the painting and achieve a rich green color. Unfortunately, over time the copper oxidizes and changes to brown.
The jewels in the painting were also analyzed with X-ray fluorescence spectroscopy. The spectrum didn’t show any evidence of a pigment that would degrade to grey or black (as the jewels currently appear). This led researchers to believe an organic pigment was used to color the jewels and has since disappeared.
It’s interesting to think that many famous paintings we admire in museums today may have looked entirely different to the artist. Beautiful landscapes depicting fall colors may have actually been an image of new spring leaves. A woman’s dress may have been green instead of brown. In any case, we can be assured there’s always an element of mystery to works of art.