18 Jun Historical traces of mural painting
The history of mural painting has started even before man learned to build brickwork buildings. In fact, in the prehistoric period there were already mural paintings (like in the Altamira Caves and in the Lascaux), although they were just simple signs traced directly on the rocky walls without a layer of plaster.
The first examples of plaster appeared in the Mesopotamian, Egyptian and Cretan art, but only later. The real fresco painting process began in fact when lime started to be put in the plasters.
In the Egyptian mural paintings, plasters were based of chalk and clay, in which sometimes was add minced straw so that the plaster would have more elasticity.
The colours were made by tempera (made of rubber or water down glues) and so the works were sensitive to humidity.
In fact, these works have been conserved thanks to the uncommonly dry climate.
However, in some Mesopotamian, Egyptian and Cretan late mural paintings there were already plaster made by sand or clay mix with lime so the colours were included in the plaster due to the lime carbonatation process and they were not washable any more.
Referring about Greeks mural painting almost no information has survived, except some recent findings (like “Tomb of the Diver”, in 450 b.C. discovered at Paestum in 1968) where the paintings denote a perfect mastery method of “good fresco”. In fact these works were done over a rough underlayer called the arriccio (based on lime and sand) and a layer (with more lime and an add of marble powder). The preparatory drawing is done directly on the plaster.
According to Vitruvio (“De Architectura” -Book VII”) the preparation of the plasters with more following layers (arriccio + plaster + intonachino) started in the Hellenistic period and then extended in the centre of Italy and therefore in Rome.
It seems the Greeks used only four colours: red, yellow, black and white.
The Etruscan (who used more colours than the Greeks) prepared the plaster spreading out on the wall a layer of clay over which then passed over with a lime milk.
In the last time even they started to prepare the plasters with sand and lime.
It is important to know the Roman painting technique when examining the numerous frescos found in archaeological excavations.
In fact, while Vitruvio spoke about three layers of “arriccio” (mixture made by lime mortar and coarse sand) and three layers of plaster (made by fine sand, lime and marble powder), this process became easier and starting in II century C.E (and all through the Middle Ages) plasters were generally made with only one layer of “arriccio” and one of plaster.