Sistine Chapel ceiling of the Sistine Chapel. At the outset, the plaster, "intonaco", began to grow mold because it was too wet. Michelangelo had to remove it and start again. He then tried a new formula created by one of his assistants, Jacopo l'Indaco, which resisted mold and entered the Italian building tradition. Because he was painting "fresco", the plaster was laid in a new section every day, called a "giornata". At the beginning of each session, the edges would be scraped away and a new area laid down. The edges between "giornate" remain slightly visible; thus, they give a good idea of
Descent from Mount Sinai (Sistine Chapel) Descent from Mount Sinai (Sistine Chapel) The Descent from Mount Sinai is a fresco by the Italian Renaissance painter Cosimo Rosselli and his assistants, executed in 1481–1482 and located in the Sistine Chapel, Rome. On 27 October 1480, several Florentine painters left for Rome, where they had been called as part of the reconciliation project between Lorenzo de' Medici, the "de facto" ruler of Florence, and Pope Sixtus IV. The Florentines started to work in the Sistine Chapel as early as spring 1481, along with Pietro Perugino, who was already there. Rosselli brought with him his son-in-law, Piero di Cosimo,