Jacques Brinon, Associated Press Visitors to the Louvre in Paris line up to view Leonardo da Vinci's Mona Lisa, at center behind a protective glass covering. Click photo for larger image.

PARIS -- On Monday, April 4, for the first time in three decades, visitors to the Louvre Museum here won't see the Mona Lisa.

Leonardo da Vinci's masterpiece last left the building on a trip to Japan in 1974 and, with her freshly renovated room about to reopen, may never leave again. The vast majority of tourists in Paris visit the Louvre, and more than 90 percent of them make a bee-line for the smiling visage of Lisa Gherardini. The Louvre giftshop sells more than 330,000 Mona Lisa items annually, including 200,000 postcards, 20,000 magnets and 10,000 puzzles.

The Louvre fears irate crowds if Japanese and American visitors turn up to find an apology hanging from Lisa's empty spot on the wall. While Rembrandts, Titians and El Grecos can all spend weeks in restoration, under study or on tour, the Mona Lisa has always remained on display.

That makes life complicated for her curator of two decades, Cecile Scaillierez. The 47-year-old art historian can spend quality time with the painting only on Tuesdays, when the Louvre closes, or at odd hours. Mona Lisa's first X-ray in three decades was performed at night.

The painting's cult-like popularity presents singular problems for other Louvre staff. Museum guides moan of tourists' monomania for the painting. Guards complain of the constant noise, flashbulbs and pickpockets in her room. The seasoned expert who X-rayed her in November was so nervous he started fretting irrationally that a light bulb might fall from the ceiling and damage the work. The image requires special security after a theft and two attacks.

Now she is having her room renovated, to handle an average of more than 1,500 visitors an hour. She'll be off display for one day on April 4 while curators install her in the upgraded digs. In the meantime, she has taken over another hall full of paintings.

In short, Mona Lisa has become like so many pop icons: a prima donna who puts outrageous demands on her handlers.

Reunion de Musees Nationaux di Parigi and Journal des Arts via AP Leonardo Da Vinci's "Mona Lisa" is shown as it currently appears, left. At right is a computer-enhnaced image that shows what it would look like were it to be stripped of the multiple layers of yellow varnish, which have been added to the canvas through the centuries for protection. For several years critics and historians have been debating the advisability of restoration. The Louvre's art critic Jean-Pierre Cuzin told the Associated Press "it is absolutely out of the question to restore the Mona Lisa in any way," while British art critic Alistair Laing told the 'Journal des Arts' that he thinks "the Louvre should consider removing the varnish, just as they have in other works." In addition to the yellowing, museum officials last year determined the wood on which Mona Lisa is painted is warping. Click photo for larger image.

"It's a nuisance," says Ms. Scaillierez, the curator. "She sets her own laws" for how to organize the museum.

During Ms. Scaillierez's 20-year tenure, the idolatry has ballooned. Today Mona Lisa receives at least one fan letter a week, much of it "bizarre," the curator says. Ms. Scaillierez tries to respond to each, including a recent hand-written missive from a numerologist who claimed to have stumbled on an "INCREDIBLE" relationship between the painting's dimensions and da Vinci's birth date.

"Everybody has a discovery," Ms. Scaillierez says.

Standing in front of the painting on a recent Tuesday, Ms. Scaillierez says she takes advantage of the weekly quiet to admire Mona Lisa in peace. Despite being inconvenienced by her subject, Ms. Scaillierez says "you don't count the hours" spent with Mona Lisa.

A lover of 16th-century European art who refers familiarly to the Italian painter as "Leonard," his name in French, Ms. Scaillierez studied at the Ecole du Louvre, a prestigious Parisian art institute unrelated to the museum. In 2003 she wrote a dense 100-page book on the painting "to dispel the myths" around it. "Doing bestsellers with Leonard," she says, "is not my thing."

Neither is reading "The Da Vinci Code," the hugely popular thriller in which an elderly Louvre curator gets murdered. "It's commercial," she sniffs.

Tour guide Sonia Brunel, an art historian, also bristles at the mass-marketing of the Mona Lisa. She says she often has a hard time getting near the painting to explain it. Instead, she talks standing across the room and waits for tourists to snap each other's portrait with the portrait. She usually starts tours in Mona Lisa's room to get it out of the way so she can "be more relaxed" on her circuit, although she would rather walk the museum in chronological order.

Not everyone complains. Louvre security supervisor Marthe Duro recalls her days guarding Mona Lisa as "a privilege." She adds that guards on Mona Lisa duty "really earn a day's wages."

Jean-Pierre Mohen, director of the Center for Research and Restoration of the Museums of France, who handled the X-ray last fall, recalls the moments when he paused to admire da Vinci's "genius" in Mona Lisa's hands and eyes, unfettered by protective glass. "Those were powerful moments," he says.

Even curators of the Louvre's other artworks, which most tourists rush past to see the Mona Lisa, don't begrudge Mona Lisa's popularity. Grousing about that would be "like complaining of being rich," says Olivier Mesley, the Louvre's conservator of English and Spanish paintings.

Mona Lisa keeps up her brave face for people like the Greenbaum family from New York. As Steven, a student in his 20s, takes photos, his mother notes that if they visited Paris and didn't see the painting, "People would say there's something wrong with you."

That attitude is why Louvre officials recently informed 6,000 travel companies about Mona Lisa's day off. A warning pops up on the museum's Web site, and alerts now appear in 10 languages on museum maps.

On that day, Mona Lisa will return after four years to her old room, which now boasts improved lighting, better crowd circulation and special antireflection glass to protect her. The installation will happen behind closed doors on a Monday, when the Louvre is open, so that French officials can dedicate her new abode the next day -- when the Louvre is closed -- undisturbed by museum-goers.

The return is the latest leg of an eventful journey. Scholars believe that in 1503, wealthy Florentine merchant Francesco del Giocondo commissioned da Vinci to paint Lisa, his third wife, then 24. "Mona," short for madonna, is the Italian equivalent of "ma'am." Da Vinci spent almost four years applying oil paints and layers of varnish to a poplar board. Why he never delivered the portrait remains unclear. In 1516 he moved to France and took Mona Lisa. She remained there when he died in 1519.

In 1798, during the French Revolution, Mona Lisa entered the Louvre, newly converted into a museum. In 1800, Napoleon borrowed "Madame Lise" for four years to hang in his bedroom. But it was larceny that elevated the masterpiece to global fame.

Early on Aug. 21, 1911, Italian artist and Louvre employee Vincenzo Peruggia removed the painting from its frame and walked out of the closed museum. Newspapers hyped the mysterious kidnapping. The painting's return in 1913 sparked celebrations in France and Italy, where Mr. Peruggia was caught.

Back in Paris, Mona Lisa's reputation soared, although problems continued. In 1956 an attacker threw acid at the painting. Several months later an assailant threw a stone. The Louvre placed her behind glass.

Then, visiting the U.S. in 1963, she was the toast of Washington and New York. In 1974, Tokyo feted her for two months. Ever since, she's been as firmly planted in Paris as the Eiffel Tower.

"The Louvre without Mona Lisa," says Ms. Brunel, the lecturer, "wouldn't be the Louvre."

	Michel Lipchitz, Associated Press Tourists wait in line to enter the Louvre, where more than 90 percent of them are expected to try to see the Mona Lisa. Click photo for larger image.