Adhesives used for the conservation treatment of canvas paintings : deterioration manifested in the paint layer

Abstract

The initial part of this study evaluated deterioration encountered in oil canvas paintings located in Malta. Attention was focused on the alteration visible on the paint layer of canvas paintings as a result of generated stresses. Several factors were discussed in order to understand the deterioration of the paint layer due to transmitted stress. In conservation, in order to reinstate the lost stability brought on by rupture, adhesives are used. However, due to environmental influences, an adhesive may undergo alteration and become unstable. The environmental conditions in Malta, having high humidity ranges, elevated temperature and intense solar radiation, introduce the risk of degradation of the adhesive system; thus the potential deterioration of adhesives is an important aspect to study. The study considers, after careful selection, Paraloid B72, Plextol B500, Beva 371, Vinnapas CEF 10 and gelatine. Homogeneous samples of each were produced and subsequently they were subjected to ageing programmes in chambers that separately simulated the parameters mentioned above, according to Maltese climatic conditions. Certain properties of non-aged and the aged samples were then tested in order to verify and compare their suitability and stability. The results indicated that the product most capable of resisting chemical and physical changes in Maltese environmental conditions is Beva 371.