Sistine Chapel ceiling how the work progressed. It was customary for fresco painters to use a full-sized detailed drawing, a "cartoon", to transfer a design onto a plaster surface—many frescoes show little holes made with a stiletto, outlining the figures. Here Michelangelo broke with convention; once confident the "intonaco" had been well applied, he drew directly onto the ceiling. His energetic sweeping outlines can be seen scraped into some of the surfaces, while on others a grid is evident, indicating that he enlarged directly onto the ceiling from a small drawing. Michelangelo painted onto the damp plaster using a wash technique to apply
Restoration of the Sistine Chapel frescoes the summer and winter months so that changes to the atmospheric environment occur gradually. The air near the ceiling is kept at a temperate level, while the air in the lower section of the building is cooler and circulates more rapidly, with the effect that dirt particles fall towards the floor rather than being streamed upwards. Bacteria and chemical pollutants are filtered out. Environmental specifications: When the restoration of the Sistine Chapel was announced, it sparked a barrage of queries and objections from art historians around the world. One of the most vocal of these critics was James Beck, of