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
Restoration of the Sistine Chapel frescoes to the Last Judgment. The restoration was unveiled by Pope John Paul II on 8 April 1994. The final stage was the restoration of the wall frescoes, approved in 1994 and unveiled on 11 December 1999. The aims of the conservators were as follows: In 1979 Colalucci undertook a series of experiments to discover the right approach for the restoration of the frescoes of the Sistine Chapel. The investigation began by testing small areas of the wall fresco, "Conflict over the Body of Moses" by Matteo de Lecce, which had similar physical and chemical attributes to the painting techniques employed