Fresco

   A painting technique devised during antiquity to decorate the walls or ceilings of private and public buildings. It entails coating the pictorial surface with a layer of coarse lime plaster (arriccio) on which the intended scene is drawn using red earth pigment (sinopia). The painting is then carried out in sections (giornate). Each section is covered with a layer of smooth plaster (intonaco) onto which pigments diluted in water are applied while the plaster is still wet. Once the plaster dries, the paint becomes a part of the wall. This technique creates a durable image that can last for centuries. Once the fresco is completed, touchups can be made using a fresco secco method where pigment is applied to the dried wall. This technique is less durable and in time can cause the paint to flake off.