For half a millennium, Leonardo da Vinci's The Last Supper suffered many insults: Napoleon's troops defaced the mural; an Allied bomb destroyed the ceiling and an adjacent wall of the Milan monastery refectory that contains it. But some say the greatest harm to the masterpiece depicting Jesus and his 12 apostles was done by overzealous restorers. On May 27, after more than $8 million and 21 years spent on painstaking cleaning and repainting by Italian restorer Pinin Brambilla, 73, and her team, the refurbished mural was unveiled. While some people find the new Supper spectacular, many experts wonder if the lightened hues of the once-dark painting—so different from the Mona Lisa and other Leonardo works—reflect more of Leonardo or Brambilla. "The work," says French art historian Jacques Franck, "now looks ghostly."

Even before the restoration, less than half of what Leonardo painted between 1494 and 1498 remained; the experimental base containing egg and linseed oil he used began deteriorating in just a few years. The mural was repaired at least seven times, including a complete repainting of three figures in 1726. Brambilla's team decided to remove not only the accumulated grime but all of the previous repaintings, redoing some missing images in water-colors. "It's not so much a restoration but a conservation of what remains," Michele Cordaro, director of Rome's Central Institute for Restoration, told Britain's Sunday Telegraph. Even detractors agree that some lost details—such as the vivid facial expressions, shiny glassware on the table and bucolic landscape in the background—have been revealed. "What emerged is what was left of Leonardo," Brambilla insists. "It was a masterpiece."