The Cathedral contains numerous masterpieces from every age but its marble mosaic inlay and graffito floor is in many ways its most prized possession. Giorgio Vasari certainly considered it the "most beautiful..., largest and most magnificent floor ever made".The floor we see today is the product of a programme that got under way in the 14thcentury but was only completed in the 19th century. The preparatory cartoons for the fifty-six inlay panels were supplied by leading artists, all of them Sienese save for the Umbrian painter Bernardino di Betto known as Pinturicchio, who designed the inlay depicting the Mount of Wisdom in 1505. The technique used to transpose the various artists' ideas onto the floor is known as graffito and mosaic marble inlay.