The Mona Lisa is a masterpiece of western art and has been copied by many artists in the past. But one of replicas has now turned out to be something special. Experts have discovered that one of the copies, at Madrid’s famous Prado Museum, was painted by a scholar of Leonardo da Vinci at the same time he was painting the original. For a long time the Prado painting was thought to be one of the many copies that date back to the 16 th and 17th centuries. Restoration work showed that the dark background of the painting was added after the painting had been finished. After its careful removal the painting revealed a landscape that was almost the same as da Vinci’s. Modern x-ray and infrared technology show that changes in the two paintings were made at exactly the same time. Conservators at the museum claim that the two paintings were painted in the same studio not far away from each other. Still, the Renaissance original and the copy look very different from each other. The copy is much brighter while Leonardo da Vinci’s original, hanging in Paris’s Louvre has become darker over the centuries. The Louvre painting is dull with cracks in the paint. The woman also seems to be older than in the Prado copy. Art educators say that the new discovery may show some new insight into the master’s painting technique. Up to the recent discovery the Prado painting was thought to have been painted sometime in the 16th century by a Flemish artist.