Here’s the link: http://www.vatican.va/various/cappelle/sistina_vr/index.html
The paintings that you see in the Sistine Chapel were created using a technique called “fresco,” which is very ancient and has a number of interesting permutations. The basic concept of the fresco is a painting done directly onto, or into, a plaster wall, what we would refer to today as a mural. Fresco paintings are of two types: “buon fresco”, which is when the artist applies pigment directly into the wet plaster, and “a secco”, which is when the artist paints over a dried plaster surface with a conventional paint. Ancient examples of buon fresco can be found in Italy, where the Romans made extensive use of it in decorating their buildings. The most well preserved examples are inside structures that were buried by the eruption of Mount Vesuvius in Pompeii and Herculaneum. The a secco technique was used by the Egyptians and can be found still intact in many of their tomb complexes that were sealed off from the elements. The fragile watercolor paint used by the Egyptians did not last anywhere else, so the remains of their temples and homes show only the bare stone surface.
Most of the paintings in the Sistine Chapel were executed in the buon fresco style, with only a few additions being added later in the a secco style. Buon fresco is a difficult technique on account of the rapid drying time of the plaster, which begins to seal after eight to ten hours. The artist would need to do a great deal of pre-planning before each session to determine how much painting could be done in a particular day, then the wet plaster would be laid down covering just enough of the wall that it could be completely painted before it dried too much. The pigment was simply mixed with a little water and then brushed into the wet plaster, mixing with it and effectively becoming part of the wall. That is the secret to the buon fresco’s durability: as long as the plaster wall stays intact, the painting will be perfectly protected. So we begin to see an explosion of fresco paintings during the Middle Ages when they were installed in churches. Because the church was a building that was usually protected and preserved, the paintings within its walls were also similarly preserved and remain available for us to view today.
The a secco method, in which the dry plaster is painted over with watercolor, tempera, encaustic or some other paint medium, is much less permanent and is subject to being scratched or abraded off the wall. A secco painting was often used to touch up the buon fresco, especially where the seams were visible in between one day’s layer of plaster and the next. Over time the a secco paint would flake off, revealing the sections of plaster and giving a window into the artist’s process.
The paintings in the chapel were commissioned by Popes Sixtus IV and Julius II, beginning in 1480, and feature the work of some of the Renaissance’s most celebrated artists. The central tier of the walls feature a series of works by Ghirlandaio, Botticelli and Perugino that depict the lives of Moses and Jesus. But, of course, the most famous sections are the upper tier of the walls, the entire vaulted ceiling and the wall behind the altar that were painted by Michelangelo. Interestingly, Michelangelo was much more focused on sculpture and didn’t consider himself to be much of a painter, so he initially resisted the commission, but in those days if the Pope told you to do something you did it! We are all the more fortunate that that was the case.
