The objective of this article is the collection of historical and technical data from the preparation of paintings and their classification according to the materials and techniques used and to the properties thus obtained. For this classification quality analysis of painting samples has been carried out, so that the materials comprising industrial preparation layers to be discovered and established.
In the experimental stage the various factors of preparation decay such as cracks, flaking, deterioration-, which also affect the entire painting surface, have been studied. For this reason the following four basic categories of preparation have been subjected to temperature elevation, exposure to high relative humidity and exposure to UV (ultraviolet) radiation.
a. Sheer oily preparation; Its exposure to temperature above 60° C resulted to serious deteriorations, its exposure to high relative humidity did not cause any remarkable deteriorations, while its long exposure to UV radiation caused a slight decolonization.
b. Semi-absorbent preparation: Us exposure to temperature above 70″ C caused a slight colour alteration and loss of flexibility.
c. Absorbent preparation: Its exposure to high relative humidity caused serious problems of cohesion.
d. Casein preparation: Its exposure to temperature elevation and high relative humidity resulted to shrinking, distortion, cracking and loss of cohesion.