The Last Supper is one of the world's most famous paintings despite it's poor condition. It succumbed to Leonardo's experimental technique of applying oil to fresh plaster. Before Leonardo's death, the fresco began to peel away from it's surface. This is a very psychological piece, portraying the moment when Jesus announces "One of you will betray me". Leonardo is able to effectively convey the character of Judas, the betrayer, without separating him from the other disciples as had been done traditionally. The separation of the disciples into groups of three leaves Jesus alone in the center, a focus of peace amidst the movement. Behind Christ is a window that seems to give him a sort of natural halo. This piece is so striking that almost without fail people will not notice that it would be impossible to have all thirteen people seated at that table while eating. The Last Supper has been subject to several restoration efforts, the most recent ending in May 1999. The refectory of Santa Maria Delle Grazie is once more open to the Public to view this decaying masterpiece.