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X-rays solve artistic mystery

N.C. Wyeth / Christina Bisulca / Univ. of Delaware
This 1919 illustration was covered over with another painting in the 1920s by artist
N.C. Wyeth, but the color scheme was reconstructed through X-ray imaging.

Eighty-five years ago, American illustrator N.C. Wyeth painted one work of art over another, hiding a dramatic fistfight beneath a placid family portrait. Now X-ray vision has brought the long-hidden colors of that fight scene back to life - without disturbing the brush strokes layered on top.

The experiment, described today at the American Chemical Society's national meeting in Washington, is just the latest example showing how science can reveal secrets concealed beneath the surface of paintings and manuscripts.

The best-known example is Leonardo da Vinci's Mona Lisa, which was put through a laser-scanning exam a few years ago. The project produced a surprising twist: Scientists found evidence that the lady with the enigmatic smile was originally depicted with the type of veil worn by pregnant women, suggesting that the painting was done to celebrate a birth.

Other examples abound:

  • During a hospital X-ray session, a portrait of an unknown Renaissance man was detected beneath a 16th-century religious scene.
  • X-rays have brought previously hidden writings by Archimedes to light, 800 years after the text was scrubbed off the parchment in a medieval form of recycling.
  • Scientists used X-ray scans to analyze ancient artwork found behind Afghanistan's ruined Bamiyan Buddha statues - shedding new light on the origins of oil painting.
  • Last year, a method known as X-ray fluoroscopy revealed the previously unseen portrait of a mystery woman beneath Vincent van Gogh's "Patch of Grass."

X-ray fluoroscopy figures in the tale of N.C. Wyeth's double painting as well. Earlier studies, using less sophisticated devices, revealed that there was a different scene hidden beneath Wyeth's "Family Portrait," thought to have been painted between 1922 and 1924 and now held by the Brandywine River Museum in Pennsylvania.

Art historians identified the mystery painting as an illustration that turned up in printed black-and-white form in a 1919 issue of Everyman's Magazine. But they couldn't make out the fine details, and they couldn't figure out which colors Wyeth used in his palette. That's where the confocal X-ray fluorescence microscope developed at New York's Cornell High Energy Synchrotron Source, or CHESS, came in handy.

X-ray fluoroscopy involves shooting beams of X-rays at a target - such as a painter's canvas - and then collecting the fluorescent signals given off by the chemicals in the various pigments. Cadmium would point to yellow pigment, for example, and cobalt would point to cornflower blue.

The problem was that previous scans couldn't discriminate that well between different layers of paint built up on the canvas. "That's what made separating out the two images so difficult," said Jennifer Mass, an expert on art conservation at the University of Delaware and the Winterthur Museum and Country Estate.

The CHESS X-ray microscope had an advantage, in that it could be fine-tuned to focus on different depths in the paint layers. In an earlier project, Mass and her colleagues were able to figure out that a 17th-century Flemish painting was actually built up from three separate wood planks over the course of 20 years. So, in 2007, the research team - including Mass as well as CHESS researcher Arthur Woll and the University of Arizona's Christina Bisulca - set to work on Wyeth's "Family Portrait."

N.C. Wyeth / Brandywine River Museum
N.C. Wyeth's "Family Portrait" conceals another image that was painted earlier. The
painting is a study for a mural that was never completed. N.C. Wyeth is the second
figure from left, and his son Andrew Wyeth is the youth pictured at far right.

The researchers mapped out exactly which pigments were used for which areas of the hidden painting - not just blacks and whites and shades of gray, but other colors as well. They found that Wyeth used a "muted palette" of colors for the fistfight scene, dominated by pastel tones, Mass said.

"We were quite surprised, actually, by the pastel colors," she told me, "but the curators weren't at all." Even though the fistfight illustration ended up in black and white, the curators knew that Wyeth also used muted shades of color when creating such works. He felt the toned-down colors on the canvas translated well onto the black-and-white page.

Mass said the museum curators were happy to hear that the researchers' findings fell in line with what was known about Wyeth's artistic technique.

The same non-destructive X-ray procedure could be used to resurrect other illustrations that have been covered over - including several of his best-known works. And that prompts an obvious question: Why did Wyeth paint over those illustrations in the first place?

Other artists, such as van Gogh and http://www.newcriterion.com/articles.cfm/matisse-wayne-2948">Henri Matisse, reused their canvases to save money. But Wyeth did it for artistic rather than financial reasons. He once advised his son, the equally famous painter Andrew Wyeth (who passed away just this year), to try painting over old canvases in order to be "inspired by the abstract shapes from the former composition."

That's just what the elder Wyeth did in his "Family Portrait": The fistfight illustration was turned upside down, and the artist picked up on some of the shapes (like a clenched fist or the curve of a fighter's pant leg) in the later painting. If you need some help to spot the hidden shapes, take a close look at the three illustrations included in this PDF edition of Cornell University's Pawprint newspaper.

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