Restoration of the Sistine Chapel frescoes of the work. Based on this decision, according to Arguimbau's critical reading of the restoration data that has been provided, the chemists of the restoration team decided upon a solvent that would effectively strip the ceiling down to its paint-impregnated plaster. After treatment, only that which was painted "buon fresco" would remain. According to critics, the inherent problem with this approach is that it relied heavily upon an assumption that Michelangelo only painted "buon fresco", that he was always satisfied with the result at the end of the day, and that in four and a half years spent on the
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