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Art History in the Making It’s hard to believe that the surface of a painting by Vincent Van Gogh might be immaterial to art historians, but sometimes it’s what’s underneath the paint that gives the real clues to an artist’s oeuvre.
And this is where the process gets interesting. Don Johnson uses a program to lay out the thread-pattern maps of the paintings as though they were pieces of a puzzle and tries to match the thread patterns edge to edge, producing a mosaic of canvases in the order they would have been cut from a larger bolt. The moMuseums and art historians began peering beneath Don Johnson said. “He wanted a particular grade of saics make it easy to see that a particular series of the surface of paintings soon after the discovery of canvas from a particular dealer. He really liked it, for paintings — the longest has 44 Van Goghs — came X-rays, most often looking for details of the underlysome reason.” from the same bolt. ing painting or, in some cases, for evidence of works Johnson uses the software to examine a digi“If we can reconstruct a bolt or roll,” Don that had been painted over. But some aspects of tized X-ray of an entire painting. Although the mateJohnson said, “it would really help in figuring out what lies beneath a painting’s surface, what painting was done when.” such as the canvas, are invisible to He has pieced together 31 groups X-rays. To analyze a canvas, art hisof paintings from the 300 or so he’s torians have had to count the number analyzed so far. “We think each corof threads by hand, a slow and tedious responds to a different bolt of cloth,” process that gives little information he said. “The 44-painting one is the about the fabric’s weave. biggest. There are a couple in the 20 Enter self-described “Van Gogh range, and a whole bunch of pairs, freak” Don Johnson, Rice’s J.S. which probably means they’re cut from Abercrombie Professor Emeritus of smaller pieces of canvas. We’ve yet to Electrical and Computer Engineering, put everything together. That’s what who is the principal investigator on will happen this coming spring.” a new National Science Foundation He hopes to analyze more than grant to assist in the studio practice half of the 864 Van Gogh paintings project at Amsterdam’s Van Gogh known to exist. Though Rice’s Johnson Museum. “The museum wants to undoesn’t expect to get X-rays of the 200 derstand as much as they can about or so paintings in private collections, Van Gogh’s process,” he explained. he’s very close to getting half of the “What kind of paints did he use? How 600-odd museum-owned paintings. “I Don Johnson, Rice’s J.S. Abercrombie Professor Emeritus of Electrical and Computer did he paint?” need about five more,” he said, “and I’ll Engineering, shows a portion of a 44-painting mosaic of Van Goghs. On the left are the paintHe and Richard Johnson (no relabe more than halfway on the available ings, placed where they were cut from the original bolt of canvas. On the right are the matchtion), the Geoffrey S.M. Hedrick Senior Van Goghs.” ing weave patterns created from the X-rays by Johnson’s software, which allows paintings Professor of Engineering at Cornell When the Van Gogh project conto be aligned edge to edge. University, have developed a computer cludes next year, Don Johnson expects program to analyze aspects of Van to give the Amsterdam museum a comGoghs and other paintings that can’t actually be seen rial, like human skin, is invisible to X-rays, X-rays do prehensive archive of data about its collection that by X-rays but that can be inferred, creating a virtual not pass through the white lead paint applied as a can be shared and compared with other museums. fingerprint of the structure of a painting. base coat to commercially available artist canvas. Later, the team will apply the same techniques to the But the software has proved capable of revealRolls of canvas were sold to dealers, who then sold much smaller Delft School collection by Johannes ing information about the canvas, as well — importhe rolls or lengths cut from the rolls to artists. Artists Vermeer. tant in Van Gogh’s case because the canvas can tell then cut what they needed from these bolts, which —Mike Williams us a lot about not just the artist’s process, but also could be 2 meters high and 100 meters long. about the timeline in which his works were created. The X-rays show where the lead paint runs This is possible because Van Gogh was notoriously along the valleys of the weave, revealing the number Who Knew: picky about his canvas. “Van Gogh was very precise,” of threads per centimeter, vertically and horizontally. ›› › ricewhoknew.info/15
Rice Magazine
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No. 8
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2010
45