Warped Mona Lisa To Be X-Rayed

Is the Mona Lisa headed for surgery?

Leonardo da Vinci's 500-year-old painting of the woman with the mysterious smile will go under the microscope, and be X-rayed for the first time in a half-century to determine what's causing it to warp.

The world's most famous portrait, painted in Italy over several years beginning about 1505, has long been known to be fragile. The oil painting sits on a half-inch poplar board that has undergone many nips and tucks over time.

Last week, the Louvre Museum said warping was discovered during the most recent of routine checks, which are conducted every one to two years, and announced a study of the problem. The examinations are made on days that the museum is closed — allowing it to remain on public display.

Vincent Pomarede, chief curator in the Louvre's department of painting, said the study is to help determine whether past repair work is doing more harm than good — and whether new touchups are needed.

"We're launching this study to understand exactly what's happening," he told Associated Press Television News.

"On the other hand, we think perhaps at a certain time we might have to intervene, not at all on the picture layer, but the back, on the panel itself," Pomarede said.

"We are going to use the chance to examine it in ways that we've not been able to in previous years," he added, saying that high-tech microscopes would be used as well as X-rays, last taken in the 1950s.

Over the years, touchups have involved attaching a brace made of strips of wood to the back of the painting to prevent a crack in the panel from worsening.

The exact cause of the crack is unknown, Pomarede said, but was "probably accidental, probably due to extreme climatic conditions."

For curators, the worry is that the warping could one day worsen the crack, or cause the painted image to bulge. "Obviously that would be a big problem," he said.

"Today, all this isn't evolving the way we'd like it to," Pomarede said. "The convex form is warping in different ways — there is one side moving more, and faster, than the other."

Nearly all six million visitors to the Louvre each year see the Mona Lisa. It reportedly has enjoyed an increase in American visitors due to Dan Brown's best seller, "The Da Vinci Code," which included the painting in the plot.

For such a popular portrait, little is left to chance. It's housed in an air-conditioned, bulletproof and humidity-controlled glass case.

Pomarede doesn't believe the daily barrage of camera flashes by eager tourists are damaging the painting, because the glass filters out all ultraviolet and most infrared light.

"It is more likely that (the warping is due) to pieces of wood added in the 17th and 18th centuries, and again in the middle of the 20th century," Pomarede said. He suspects a "different aging pattern" of the various pieces of wood is the culprit for the warping.

Wood restoration experts are to examine how to best rehouse the Mona Lisa when it is moved into its own room at the Louvre next year. They will help decide whether changes to the level of humidity or air conditioning are required.

The work has been through hard times before. During World War II, French authorities hid it in small towns to keep it out of the hands of German forces. In 1911, an Italian house painter stole the masterpiece; it was recovered two years later in Florence and sent back to France.

With such a legacy, and the genius of Leonardo as its creator, Pomarede says he's not too worried about the painting's fate in the long run.

"Leonardo da Vinci worked brilliantly, and he knew perfectly well the evolution of materials," Pomarede said. "She's 500 years old and if we preserve her properly she will still be there 500 from now."

By Jamey Keaten