Painting on walls goes back to prehistory, when humans sketched animals, hunts, daily scenes and even their own handprints directly onto the interiors of their cave dwellings. Crude pigments made from plants, blood, red and yellow ochre (clay), charcoal, and other powdered minerals were used to render the images. Some wall art dates to 64,000 years ago.

Wall painting persists in the form of frescoes – the art of painting murals directly onto wet plaster with brushes dipped in colorful pigments. Like the works in paleolithic caves, as long as the plaster lasted, the painting did, too.

Ancient Greeks and Romans routinely used frescoes for decorating private homes, public buildings, palaces and temples. Frescoes from Pompeii continue to be excavated from the volcanic ash that buried the city in the year 79 A.D., and emerge looking as bright and colorful as they were when they were new. Frescoes became prominent in churches, cathedrals, and even in mosques and temples from the medieval period through the late Renaissance era.

Frescoes are created in two distinct techniques known as buon fresco and secco fresco. While the methods appear similar, the final results are distinctively different.

Buon Fresco

Buon fresco (Italian for “true fresh”) calls for mural imagery to be painted directly onto a specially-prepared three-layer wet plaster compound called intonico (Italian for “plaster”). As it dries, the plaster absorbs the pigments and the mural becomes part of the wall or ceiling itself. Buon fresco is durable as long as the plaster remains intact.

Tiziano Lucchesi, an instructor in fresco painting at the Studio Arts College International in Florence, Italy, explains the process of painting buon frescoes in three steps: “The background is laid out with a basic primer color while plaster is still wet … once the water is evaporated more, other colors can be added … before evaporation occurs … [and] … the last phase is where the evaporation is near complete and only retouches are possible.” Once the surface is ready, a charcoal or painted drawing, known as a cartoon, is laid over the top to provide the outline for the finished fresco.

Artists using the buon fresco technique must grapple with an unforgiving deadline to complete the work before the plaster dries completely. If it does, the buon fresco itself will be difficult to correct. Michelangelo’s images on the walls of the Sistine Chapel at the Vatican might be the finest and best-known examples of buon fresco.

Secco Fresco

Secco fresco (Italian for “dry fresh”) requires painting mural scenes directly onto existing dry plaster. The target surface must be soaked with lime water before painting can begin. While the palette of paints for a buon fresco are made from a mix of dry pigment and water, those readied for a secco fresco require binders such as egg yolk, oil or glue.

Because the plaster is relatively dry, the artist has more time to complete a secco fresco than a buon fresco, but the technique has a significant disadvantage: the colors aren’t readily absorbed into the plaster and thus aren’t as durable. Leonardo da Vinci’s The Last Supper is the best-known example of the secco fresco technique. The religious masterpiece has weathered the centuries poorly, demanding endless maintenance.

A sort of in-between technique, known as mezzo fresco (“medium fresh”), attempts to preserve the looser time schedule granted by secco fresco while strengthening the durability of the image it produces. Artists relying on mezzo fresco add lime water to their pigments in order to bind them more securely to the almost-dry plaster.

How to Tell the Difference Between the Two

According to experts, a quick way to spot the technique used to create a fresco is to assess its surface. Buon fresco is smoother overall; secco fresco is painted on existing dry plaster, which has a rougher appearance. Also, secco frescoes will noticeably craze, split and flake off, requiring constant attention and upkeep.

Schools of Fresco Painting

Painting on fresh plaster as a deliberate artistic style can be traced back at least 4,000 years, to the Minoan civilization near Crete. Middle Eastern, Mediterranean, Roman and Northern African fresco paintings are prevalent on tombs, private homes, peristyles and public buildings from the ancient world. Catacombs in Rome feature buon fresco murals from the early Christian era. Even caves in the Indus Valley have examples of fresco murals from at least 1100 B.C., such as in the Brihadisvara Temple in India. These are all examples of very early fresco painting. Such works tend to head straight to national museums and are not usually made available at auction.

Churches, cathedrals and houses of worship all relied on fresco murals to teach the lessons of the Bible in the 12th and 13th centuries. Many medieval fresco murals enliven the structures of the Eastern Orthodox community, such as Andrei Rublev’s frescoes in several prominent Moscow cathedrals. Giotto’s Betrayal of Christ, painted in 1305, is a celebrated medieval fresco that graces the Arena Chapel in Padua, Italy.

The Italian Renaissance period was something of a golden age for fresco, with works rendered by Botticelli, Coreggio, and Massacio, as well as Michelangelo, whose Sistine Chapel frescoes became part of the very fabric of the ceiling of the Vatican. The painter known as Raphael created The School of Athens, one of the highest forms of fresco painting in the Vatican, completing it in 1511. Artists routinely painted frescoes until the early 16th century, when the medium’s use slowed considerably in favor of small and large oil paintings, which were far more portable.

The Baroque period, which spanned the late-16th to mid-18th century, marks the last great era for the fresco. Artists such as Pietro da Cortana, Carlo Miratta, and Tiepolo, whose frescoes featured in the Wurzburg Residences series of the 1750s, represented the last of the Italian Grand Manner painters of fresco art along with the Bolognese School.

After the Baroque Period, the use of fresco for enlivening interiors declined as an art form, although some artists, includingTheodore Chasseriau and Puvis de Chavannes, did work in the medium into the late 19th century.

A few early 20th-century artists such as Diego Rivera, Francesco Clemente, David Siqueros and Jose Orozco, embraced the fresco technique as they led Mexican Muralism into prominence as part of a public art movement. Some projects commissioned by the Works Progress Administration (WPA) in the United States during the Great Depression featured secco frescoes by local artists that are still displayed in public buildings such as city halls, post offices and state capitals.

While it is not as dominant an art form as it once was, fresco painting continues to be taught online and at art schools. Budding and experienced art collectors will find examples at all levels with which to start, or enhance, any collection, and range from cartoons, studies and preparatory works to actual fragments or panels recovered from a building.