Leonardo was and is renowned[2] primarily as a painter. Among his works, the Mona Lisa is the most famous and most parodied portrait[4] and The Last Supper the most reproduced religious painting of all time, with their fame approached only by Michelangelo's The Creation of Adam.[1] Leonardo's drawing of the Vitruvian Man is also regarded as a cultural icon,[5] being reproduced on items as varied as the euro, textbooks, and T-shirts. Perhaps fifteen of his paintings survive, the small number because of his constant, and frequently disastrous, experimentation with new techniques, and his chronic procrastination.[nb 2] Nevertheless, these few works, together with his notebooks, which contain drawings, scientific diagrams, and his thoughts on the nature of painting, compose a contribution to later generations of artists rivalled only by that of his contemporary, Michelangelo.…