Due to the methods used, and a variety of environmental factors, as well as intentional damage, very little of the original painting remains today, despite numerous restoration attempts, the last being completed in 1999.
The opposite wall of the refectory is covered by the Crucifixion fresco by Giovanni Donato da Montorfano, to which Leonardo added figures of the Sforza family in tempera. (These figures have deteriorated in much the same way as has The Last Supper.)
