 It is believed, through early copies, that Jesus' feet were in a position symbolizing the forthcoming crucifixion.In 1768, a curtain was hung over the painting for the purpose of protection; it instead trapped moisture on the surface, and whenever the curtain was pulled back, it scratched the flaking paint.A first restoration was attempted in 1726 by Michelangelo Bellotti, who filled in missing sections with oil paint then varnished the whole mural.