DURHAM, N.C. | A Duke University professor who developed a laser to study melanoma has discovered a new use for the system: uncovering what's underneath artwork without damaging the pieces in any way.
Dr. Warren S. Warren was at the National Gallery in London, looking at an exhibit on art forgeries, when he realized that the art world used imaging technologies that were 30 or 40 years old. So he began investigating whether lasers could be used to uncover the mysteries underneath layers of paint without damaging the art.
So far, the answer is a qualified yes.
Warren and others in Duke's Center for Molecular and Biomedical Imaging, which he heads, have discovered they can use Warren's pump-probe laser to create three-dimensional cross-sections of art that let researchers see colors, layers and maybe, at some point, discover the source of materials.
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“It's not ready for primetime, but it's showing some real promise, and that's exciting,” said John Delaney, senior imaging scientist in the conservation division of the National Gallery of Art in Washington, D.C. Delaney, who researches how to adapt noninvasive analytical imaging methods to help identify and map artists' materials, has traveled to Durham to see the laser system at work.
The first beneficiary of the laser is the N.C. Museum of Art, about 60 miles southeast of Durham. The museum and the school are figuring out together how to make the pump-probe laser work optimally for art conservationists.
The museum's 14th-century “Crucifixion” by Puccio Capanna was the first painting to get a pump-probe laser exam. It revealed a thick layer of lapis lazuli over Madonna's mantle, said William Brown, the museum's chief conservator. Typically, that blue is achieved with a layer of the less expensive azurite, covered with a thin layer of lapis, which was more expensive than gold at the time, he said.
“This tells us it was a really important painting,” said Brown, adding that it could be part of an altarpiece at the Vatican.
The museum is contributing about $12,500 a year in grant funds to research its paintings, while the school received a three-year grant of about $700,000 from the National Science Foundation to investigate the laser's use for both cancer and art research. Warren's lab will use part of the NSF grant to develop a portable version of the pump-probe so it can go to the paintings, rather than the other way around, and so it can be used to examine larger works of art.
The research matters well beyond telling visitors that another face lies under the one they see now or that the red glaze and lapis paint were mixed, rather than layered, Brown said.
“Through these techniques, you're also understanding the technology that went into the creation of these paintings,” Brown said. “And you can chart the whole history of the world through technology and technology innovations. It affects the economy, it affects everything.”