Fresco ( or frescoes) is a technique of mural painting executed upon freshly laid ("wet") lime plaster. Water is used as the vehicle for the dry-powder pigment to merge with the plaster, and with the setting of the plaster, the painting becomes an integral part of the wall. The word fresco () is derived from the Italian adjective fresco meaning "fresh", and may thus be contrasted with fresco-secco or secco mural painting techniques, which are applied to dried plaster, to supplement painting in fresco. The fresco technique has been employed since antiquity and is closely associated with Italian Renaissance painting.
The word fresco is commonly and inaccurately used in English to refer to any wall painting regardless of the plaster technology or binding medium. This, in part, contributes to a misconception that the most geographically and temporally common wall painting technology was the painting into wet lime plaster. Even in apparently buon fresco technology, the use of supplementary organic materials was widespread, if under-recognized.
Technology
Buon fresco pigment is mixed with room temperature water and is used on a thin layer of wet, fresh plaster, called the intonaco (after the Italian word for plaster). Because of the chemical makeup of the plaster, a binder is not required, as the pigment mixed solely with the water will sink into the intonaco, which itself becomes the medium holding the pigment. The pigment is absorbed by the wet plaster; after a number of hours, the plaster dries in reaction to air: it is this chemical reaction which fixes the pigment particles in the plaster.
The chemical processes are as follows: calcination of limestone in a lime kiln: CaCO3 → CaO + CO2 slaking of quicklime: CaO + H2O → Ca(OH)2 setting of the lime plaster: Ca(OH)2 + CO2 → CaCO3 + H2O
In painting buon fresco, a rough underlayer called the arriccio is added to the whole area to be painted and allowed to dry for some days. Many artists sketched their compositions on this underlayer, which would never be seen, in a red pigment called sinopia, a name also used to refer to these under-paintings. Later, new techniques for transferring paper drawings to the wall were developed. The main lines of a drawing made on paper were pricked over with a point, the paper held against the wall, and a bag of soot (spolvero) banged on them to produce black dots along the lines. If the painting was to be done over an existing fresco, the surface would be roughened to provide better adhesion. On the day of painting, the intonaco, a thinner, smooth layer of fine plaster was added to the amount of wall that was expected to be completed that day, sometimes matching the contours of the figures or the landscape, but more often just starting from the top of the composition. This area is called the giornata ("day's work"), and the different day stages can usually be seen in a large fresco, by a faint seam that separates one from the next.
Buon frescoes are difficult to create because of the deadline associated with the drying plaster. Generally, a layer of plaster will require ten to twelve hours to dry; ideally, an artist would begin to paint after one hour and continue until two hours before the drying time—giving seven to nine hours' working time. Once a giornata is dried, no more buon fresco can be done, and the unpainted intonaco must be removed with a tool before starting again the next day. If mistakes have been made, it may also be necessary to remove the whole intonaco for that area—or to change them later, a secco. An indispensable component of this process is the carbonatation of the lime, which fixes the colour in the plaster ensuring durability of the fresco for future generations.How is a fresco made? - Fresco Blog by Italian Fresco Blog.
A technique used in the popular frescoes of Michelangelo and Raphael was to scrape indentations into certain areas of the plaster while still wet to increase the illusion of depth and to accent certain areas over others. The eyes of the people of the School of Athens are sunken-in using this technique which causes the eyes to seem deeper and more pensive. Michelangelo used this technique as part of his trademark 'outlining' of his central figures within his frescoes.
In a wall-sized fresco, there may be ten to twenty or even more giornate, or separate areas of plaster. After five centuries, the giornate, which were originally nearly invisible, have sometimes become visible, and in many large-scale frescoes, these divisions may be seen from the ground. Additionally, the border between giornate was often covered by an a secco painting, which has since fallen off.
One of the first painters in the post-classical period to use this technique was the Isaac Master (or Master of the Isaac fresco, and thus a name used to refer to the unknown master of a particular painting), in the Upper Basilica of Saint Francis in Assisi.
Other types of wall painting
A secco or fresco-secco painting is done on dry plaster (secco meaning "dry" in Italian). The pigments thus require a binding medium, such as egg (tempera), glue or oil to attach the pigment to the wall. It is important to distinguish between a secco work done on top of buon fresco, which according to most authorities was in fact standard from the Middle Ages onwards, and work done entirely a secco on a blank wall. Generally, buon fresco works are more durable than any a secco work added on top of them, because a secco work lasts better with a roughened plaster surface, whilst true fresco should have a smooth one. The additional a secco work would be done to make changes, and sometimes to add small details, but also because not all colours can be achieved in true fresco, because only some pigments work chemically in the very alkaline environment of fresh lime-based plaster. Blue was a particular problem, and skies and blue robes were often added a secco, because neither azurite blue nor lapis lazuli, the only two blue pigments then available, works well in wet fresco.All this section - Ugo Procacci, in Frescoes from Florence, pp. 15–25 1969, Arts Council, London.
It has also become increasingly clear, thanks to modern analytical techniques, that even in the early Italian Renaissance painters quite frequently employed a secco techniques so as to allow the use of a broader range of pigments. In most early examples this work has now entirely vanished, but a whole painting done a secco on a surface roughened to give a key for the paint may survive very well, although damp is more threatening to it than to buon fresco.
A third type called a mezzo-fresco is painted on nearly dry intonaco—firm enough not to take a thumb-print, says the sixteenth-century author Ignazio Pozzo—so that the pigment only penetrates slightly into the plaster. By the end of the sixteenth century this had largely displaced buon fresco, and was used by painters such as Giovanni Battista Tiepolo or Michelangelo. This technique had, in reduced form, the advantages of a secco work.
The three key advantages of work done entirely a secco were that it was quicker, mistakes could be corrected, and the colours varied less from when applied to when fully dry—in wet fresco there was a considerable change.
For wholly a secco work, the intonaco is laid with a rougher finish, allowed to dry completely and then usually given a key by rubbing with sand. The painter then proceeds much as he or she would on a canvas or wood panel.
History
Egypt and ancient Near East The first known Egyptian fresco was found in Tomb 100 at Hierakonpolis, and dated to . Several of the themes and designs visible in the fresco are otherwise known from other Naqada II objects, such as the Gebel el-Arak Knife. It shows the scene of a "Master of Animals", a man fighting against two lions, individual fighting scenes, and Egyptian and foreign boats. Ancient Egyptians painted many tombs and houses, but those wall paintings are not frescoes.Nina M. Davies: Ancient Egyptian paintings, Vol. III, Chicago, 1963, p. xxxi online
An old fresco from Mesopotamia is the Investiture of Zimri-Lim (modern Syria), dating from the early 18th century BC.
Aegean civilizations
The oldest frescoes done in the buon fresco method date from the first half of the second millennium BCE during the Bronze Age and are to be found among Aegean civilizations, more precisely Minoan art from the island of Crete and other islands of the Aegean Sea. The most famous of these, the Bull-Leaping Fresco, depicts a sacred ceremony in which individuals jump over the backs of large bulls. The oldest surviving Minoan frescoes are found on the island of Santorini (classically known as Thera), dated to the Neo-Palatial period ().
While some similar frescoes have been found in other locations around the Mediterranean basin, particularly in Egypt and Morocco, their origins are subject to speculation. Some art historians believe that fresco artists from Crete may have been sent to various locations as part of a trade exchange, a possibility which raises to the fore the importance of this art form within the society of the times. The most common form of fresco was Egyptian wall paintings in tombs, usually using the a secco technique.
Classical antiquity
Frescoes were also painted in ancient Greece, but few of these works have survived. In southern Italy, at Paestum, which was a Greek colony of the Magna Graecia, a tomb containing frescoes dating back to 470 BC, the so-called Tomb of the Diver, was discovered in June 1968. These frescoes depict scenes of the life and society of ancient Greece, and constitute valuable historical testimonials. One shows a group of men reclining at a symposium, while another shows a young man diving into the sea. Etruscan frescoes, dating from the 4th century BC, have been found in the Tomb of Orcus near Veii, Italy.
The richly decorated Thracian frescoes of the Tomb of Kazanlak are dating back to 4th century BC, making it a UNESCO-protected World Heritage Site.
Roman wall paintings, such as those at the magnificent Villa dei Misteri (1st century BC) in the ruins of Pompeii, and others at Herculaneum, were completed in buon fresco.
Roman (Christian) frescoes from the 1st to 2nd centuries AD were found in catacombs beneath Rome, and Byzantine icons were also found in Cyprus, Crete, Ephesus, Cappadocia, and Antioch. Roman frescoes were done by the artist painting the artwork on the still damp plaster of the wall, so that the painting is part of the wall, actually colored plaster. A historical collection of Ancient Christian frescoes can be found in the Churches of Göreme.
India
Thanks to large number of ancient rock-cut cave temples, valuable ancient and early medieval frescoes have been preserved in more than 20 locations of India.Ancient and medieval Indian cave paintings - Internet encyclopedia by Wondermondo. Retrieved 4 June 2010. The frescoes on the ceilings and walls of the Ajanta Caves were painted between and are the oldest known frescoes in India. They depict the Jataka tales that are stories of the Buddha's life in former existences as Bodhisattva. The narrative episodes are depicted one after another although not in a linear order. Their identification has been a core area of research on the subject since the time of the site's rediscovery in 1819. Other locations with valuable preserved ancient and early medieval frescoes include Bagh Caves, Ellora Caves, Sittanavasal, Armamalai Cave, Badami Cave Temples and other locations. Frescoes have been made in several techniques, including tempera technique.
The later Chola paintings were discovered in 1931 within the circumambulatory passage of the Brihadisvara Temple in India and are the first Chola specimens discovered.