Fresco is a way of painting on a wall while its lime plaster is still wet. The painter brushes on pigments mixed with nothing but water, and as the plaster dries and hardens, the color is locked inside the wall instead of sitting on its surface.
The best known example is Michelangelo's ceiling in the Sistine Chapel, the pope's own chapel in the Vatican, painted between 1508 and 1512.
The name comes straight from the method. Fresco is short for the Italian affresco, "in the fresh." Paint laid on plaster that has already dried has its own name, a secco, "on the dry," and it does not count as fresco.
Cool Stories About Art is a newsletter to learn art the fun way.
Join 200,000+ readers and get:
10 new art stories / month
The entire archive of content (140+ articles)
Comment, ask questions, and chat with other readers
Working in the fresh sets the pace. Lime plaster starts to harden within hours of being spread, and once it has set, the color can no longer sink in. So a fresco is painted in patches, one day's surface at a time.
Why the color stays in the wall
The color stays because of what the lime does as it dries…
What You'll Discover
Why unfinished plaster is cut away each evening.
Why skies were often painted after the wall dried.
Why Milan's most famous wall painting began to flake.
The mold that nearly stopped Michelangelo.
What the seams in a wall reveal.