In a wall-sized fresco, there may be ten to twenty or even more giornate, or separate areas of plaster. Michelangelo used this technique as part of his trademark 'outlining' of his central figures within his frescoes. 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. Ī 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. 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.Īn 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. 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. 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.

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.īuon frescoes are difficult to create because of the deadline associated with the drying plaster. 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.

If the painting was to be done over an existing fresco, the surface would be roughened to provide better adhesion. 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. Later, new techniques for transferring paper drawings to the wall were developed. 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. 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.

setting of the lime plaster: Ca(OH) 2 + CO 2 → CaCO 3 + H 2OĪ Roman fresco of a young man from the Villa di Arianna, Stabiae, 1st century AD.

slaking of quicklime: CaO + H 2O → Ca(OH) 2.

calcination of limestone in a lime kiln: CaCO 3 → CaO + CO 2.

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. 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. Detail of two dancers from the Tomb of the Triclinium in the Necropolis of Monterozzi 470 BC, Tarquinia, Lazio, Italyīuon 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). Even in apparently Buon fresco technology, the use of supplementary organic materials was widespread, if underrecognized. This, in part, contributes to a misconception that the most geographically and temporally common wall painting technology was the painting into wet lime plaster. The word fresco is commonly and inaccurately used in English to refer to any wall painting regardless of the plaster technology or binding medium. The fresco technique has been employed since antiquity and is closely associated with Italian Renaissance painting. The word fresco ( Italian: affresco) 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. 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 Creation of Adam, a detail of the fresco Sistine Chapel ceiling by Michelangeloįresco (plural frescos or frescoes) is a technique of mural painting executed upon freshly laid ('wet') lime plaster. For other uses, see Fresco (disambiguation).

Painting plaster art