The medium of choice for artists in the Italian Renaissance was largely fresco, which is created when paint is applied to wet plaster. Somebody painting a fresco has to work very quickly because the plaster dries rapidly. Everything from Michelangelo's Sistine Chapel ceiling to Masaccio's Holy Trinity was painted with fresco.
Want to impress people at your next cocktail party with a little trivia? Da Vinci's The Last Supper is not a fresco. Da Vinci experimented with a new type of paint when he was creating The Last Supper, a type of paint which almost immediately started to flake off the wall. We're sure conservators are having a ball trying to stop one of the world's most famous paintings from falling off of the wall.