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
Primavera (painting) Three Graces of the "Primavera". (Kenneth Clark) The origin of the painting is unclear. Botticelli was away in Rome for many months in 1481/82, painting in the Sistine Chapel, and suggested dates are in recent years mostly later than this, but still sometimes before. Thinking has been somewhat changed by the publication in 1975 of an inventory from 1499 of the collection of Lorenzo di Pierfrancesco de' Medici. The 1499 inventory records it hanging in the city palace of Lorenzo di Pierfrancesco de' Medici and his brother Giovanni "Il Popolano". They were the cousins of Lorenzo de' Medici ("Lorenzo il