Fresco

Fresco (plural frescos or frescoes) is a technique of mural painting executed upon freshly-laid, or wet lime plaster. Water is used as the vehicle for the 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 (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. The fresco technique has been employed since antiquity and is closely associated with Italian Renaissance painting.

Technology

Buon fresco pigment mixed with water of room temperature on a thin layer of wet, fresh plaster, for which the Italian word for plaster, intonaco, is used. 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: