Restoration of the Sistine Chapel frescoes and by the painting of the "Last Judgment", commissioned by Pope Clement VII and completed in 1541, again by Michelangelo. The tapestries on the lowest tier, today best known from the Raphael Cartoons (painted designs) of 1515–16, completed the ensemble. Together the paintings make up the greatest pictorial scheme of the Renaissance. Individually, some of Michelangelo's paintings on the ceiling are among the most notable works of western art ever created. The frescoes of the Sistine Chapel and in particular the ceiling and accompanying lunettes by Michelangelo have been subject to a number of restorations, the most recent taking place
Restoration of the Sistine Chapel frescoes have been predicted by previous restorers. One of the major dangers to the frescoes is automotive exhaust, and they are also vulnerable to the effects of the crowds of tourists that pass through the chapel every day, bringing with them heat, humidity, dust and bacteria (the latter of which can biodegrade paints and pigments). The clean plaster surfaces are more in danger from these destructive elements than they were when they were covered with a layer of smoky wax. Previously, the Sistine Chapel's only ventilation was from its windows in the upper level of the walls. To prevent exhaust fumes