fresco

Imagine artists centuries ago, painting quickly on wet plaster walls: that is a fresco. It is an old mural-painting method in which water-based color is put directly onto fresh lime plaster. As the wall dries, the color becomes part of the surface, which is why these paintings can last for a very long time. You can think of the bright scenes in Roman villas or the painted ceilings of Renaissance churches.

The word comes from Italian and means "fresh," pointing to the damp plaster needed for the work. People usually use fresco when talking about art history, old buildings, or famous wall paintings, especially in Europe. It can mean both the technique and the painting made with that technique. Michelangelo's Sistine Chapel ceiling is one of the best-known examples. A true fresco must be planned carefully because once the plaster dries, it is very hard to change.

A fresco is both a method of mural painting and the wall painting produced by that method. The classic process is done on freshly laid, wet lime plaster. The artist applies pigments mixed with water to the intonaco (the final thin layer of plaster) while it is still damp. As the plaster sets, a chemical process called carbonation occurs, turning the lime into calcium carbonate. This locks the color into the wall itself, which is why many frescoes remain in place for centuries or even longer.

There are two main variations of the technique. Buon fresco ("true fresco") is the most traditional and demanding method, involving painting on wet plaster in sections called giornate (meaning "a day's work"). Whatever the artist does not finish before the plaster dries must be removed and replaced the next day. In contrast, fresco-secco ("dry fresco") means painting on dry plaster. While secco allows a wider range of colors and finer detail, it is less permanent and more likely to flake over time.

The technique flourished in the ancient Minoan civilization, in Rome, and throughout the Italian Renaissance. Famous examples include the "Bull-Leaping" fresco at Knossos, the preserved murals of Pompeii, and Michelangelo's monumental work in the Sistine Chapel. Today, the term is sometimes used loosely for any large wall painting, but in its strict sense it refers to art made on fresh plaster. At its heart, a fresco is tied to that "fresh" surface and to the long life that surface can give the image.