The Cenacolo, also known as the Last Supper, is a wall painting, often improperly described as a fresco[1], executed with a mixed “dry” technique on plaster (460×880 cm) by Leonardo da Vinci, dated 1494–1498 and made on commission from Ludovico il Moro in the refectory of the convent adjoining the sanctuary of Santa Maria delle Grazie in Milan.

«He used to… go early in the morning to climb up onto the scaffold, because the Cenacolo is somewhat high off the ground; he would, I say, from the rising sun until evening never take the brush from his hand, but, forgetting food and drink, paint continually. Then he would spend two, three, even four days without touching it, yet sometimes he would remain for an hour or two during the day merely contemplating, considering, and within himself judging his figures. I have also seen him, as whim or fancy moved him, leave at midday, when the sun is in Leo, the Corte Vecchia where he was modeling that astounding clay horse, and come straight to Le Grazie; mounting the scaffold he would take the brush and give one or two strokes to one of those figures, and usually depart and go elsewhere.» (Matteo Bandello, Novella LVIII) Novella LVII