A few years ago I had the immense pleasure of visiting the Louvre, tempered only by the immense annoyance that the choir I was touring with had to be somewhere else that afternoon, leaving us with a grand total of 45 minutes to spend in the world’s most famous art museum.
Among the few paintings I had time to admire, however, was the world’s most famous: the Mona Lisa. Leonardo da Vinci is a personal hero of mine, so I was thrilled to see his work in person, while at the same time taken aback by its actual appearance: relatively small (75 centimetres by 54 centimetres, to be precise), dark, and hard to see inside its climate-controlled compartment.
The Mona Lisa is being moved from that small compartment to a room of its own, which won’t be ready until 2001. Some art experts are advocating taking advantage of the move to completely restore the painting, as well, using modern, high-tech techniques similar to those recently used to restore Michelangelo’s frescoes in the Sistine Chapel.
The French art magazine Journal des Arts recently published two photos of the Mona Lisa, one as-is, the other computer-enhanced to show what it might look like if properly restored to its 1503 glory: cheeks rosy instead of jaundiced, pale blue skies instead of the apparent orange glow of sunset.
The Louvre is resisting those calls, claiming new lighting and non-reflective glass in the new gallery will enhance the appearance of the painting without any other restoration work being carried out, but many experts feel there’s no reason to treat the Mona Lisa any differently from any other painting–and the Louvre has restored many other ancient treasures.
What plagues the Mona Lisa is the same thing that plagues many old paintings: a bad case of yellowed varnish. Over the past 495 years, the painting has been plastered with resin, lacquer and varnish at various times. Light causes those substances, originally clear, to darken with age. Removing them is tricky, because each different substance requires a different solvent, and those solvents, in turn, must not damage the paint that lies underneath everything.
Varnish isn’t the only problem, either. Many of the world’s greatest paintings predate electric light by centuries, which means they hung in halls filled with the smoke of candles, oil lamps and open fires. (Contemporary records indicate that the Brancacci Chapel in Florence, to give just one example, burned half a barrel of oil in its votive lamps every day in the year 1516.)
Cracking of the paint is a common problem in old paintings, especially along the periphery, where the canvas is in contact with the bars used to stretch the canvas prior to painting. Over the years the canvas relaxes, causing the paint to crack. Sometimes, it even flakes off. Sometimes the canvas itself has deteriorated badly.
To top it all off, paintings have sometimes been “restored” by means of having a lesser-talented artist repaint portions of it–and sometimes, elements of the original have been painted over completely to hide an offending element. (In the Sistine Chapel, for example, 16th century Vatican artists painted in strips of cloth to hide the nudity of Michelangelo’s original figures. In another case, a coat of arms that originally appeared in Tintoretto’s Paradiso was painted over with a cloud.)
To help them successfully restore paintings, conservators today can turn to a number of high-tech tools and methods. Figuring out the right solvents to use to remove varnish and lacquer, for instance, requires accurate analysis of the chemical makeup of that varnish and lacquer. At conservation facilities like the Canadian Conservation Institute in Ottawa, infrared spectroscopy is one of the tools used to accomplish that analysis. Infrared spectroscopy is based on the fact that the chemical bonds of different molecules absorb infrared radiation in specific ways. Analyzing how a substance reacts to infrared radiation can tell you its chemical makeup. X-ray diffraction uses X-rays to accomplish the same feat.
Other high-tech methods are used to peer beneath the layers of lacquer and varnish, and even beneath the paint applied by retouchers, to see what the original work looked like, or even to trace the artist’s revisions of the work. Infrared reflectoscopy is based on the fact that some pigments that reflect visible light are transparent to infrared light (cadmium red, for instance). X-ray analysis can sometimes show you the same thing. By adding computers to mix, restorers can superimpose an image of the artwork over the infrared or X-ray images, making it easy to see any differences.
Computers also aid in major restoration projects like the Sistine chapel simply by making it possible for restorers to instantly access an enormous database of information. In the case of the Sistine chapel, for instance, a computer programmed to map every curve and crack in the ceiling down to the last millimetre proved so valuable they installed it 20 meters above the ground on the main scaffold.
The restoration work itself is incredibly painstaking. Cleaning a painting is done with cotton swabs, a little at a time. Places where paint is missing are carefully filled in by trained artists using watercolours, followed by powder pigments in a stable resin medium. Weakened canvas may be attached to a polyester lining using microcrystalline wax. Finally, a new natural resin varnish–one designed not to yellow with age–is placed over the entire surface of the painting to protect it.
An “ordinary” painting, like one the Canadian Conservation Institute recently restored for a Quebec church, can take two years to restore. The Sistine Chapel, by way of contrast, took 13 years to restore–more than twice as long as Michelangelo took to paint it.
And although no one has a problem with restoring most old paintings, many people do have philosophical qualms about restoring cultural icons like the Sistine Chapel or the Mona Lisa. People used to seeing the Sistine Chapel in sepia tones were startled, even offended, to see it in its newly restored technicolor glory. (“The Sistine Chapel: Still Michelangelo?” is the name of an actual course at one U.S. college.) After all, who’s to say that the colors weren’t somehow artificially heightened by the restoration process? We may not really be seeing what Michelangelo really painted than we were before the restoration.
Some of the same concerns influence the debate over restoring the Mona Lisa. Some experts doubt that there are any remarkably different colors to be seen beneath the Mona Lisa’s aging varnish; they believe Da Vinci naturally used more muted colors, mostly brown and gray, than artists like Raphael.
In any event, the Louvre is sticking by its guns, for now. “It’s absolutely out of the question to restore the Mona Lisa in aany way,” says Jean-Pierre Cuzin, chief paintings’ curator at the Louvre. “We’d rather wait until we’re sure that a cleaning wouldn’t do any irreparable damage.”
That may be a relief to the world’s top art restorers. Jean-Gabriel Goulinat worked on the Mona Lisa off and on for more than 30 years (several age spots were removed in the 1950s). He considers himself lucky to be alive. Says Goulinat, “If you want a restoration expert to commit suicide, put him to work on the Mona Lisa.”