or Craquelure (french term meaning cracking). Indicates the eventual cracking present on the pictorial surface. Among the various types of craquelure (characterized by different designs and originating from diverse causes), one may distinguish between drying cracks and ageing cracks. The former is determined in the initial phase of the life of the pictorial film when the methods and materials are used improperly and internal chemical variations occur which causes the contraction of the material. On the other hand, ageing cracks develop in a painting that is already dry and incapable of withstanding the mechanical movements that the support allows due to the varying humidity and temperature of the environment. If the ageing cracks can be preserved and in fact appreciated as a sign of the work in time, the craquelé originating from an uneven drying of the different layers of colour may determine a sliding of one layer over another, with widened cracking and with the colour coagulated in elevated blocks (Crocodile skin craquelure).