Chemie in der Freskomalerei: Kunst, Computer, Chemie

Prehistoric cave paintings have been conserved for about 15000 to 20000 thousand years. As modern investigations have shown the applied pigments are covered with a surface film of crystallized lime.This is the principle used when fresco-painting. The pigments are painted on freshly applied, wet lime-water walls or ceilings. During the process of ripening carbon dioxide is absorbed from atmosphere. Lime mortar is hardening, the pigments dry with the plaster to become a permanent part of brickwork. Though fresco buono (= true fresco)is the most durable technique it depends sensitively on processes of acid-base-equilibria. Thus, fresco-paintings are „in dialogue”︁ with environmental conditions for all times. The physico-chemical principles of fresco-painting are discussed and demonstrated.