Badanie osłon odwroci obrazów malowanych na płótnie

The protection of the reverse side of canvas paintings as a method of their preservation has been known for a long time. The problem has often been discussed in literature on preservation. The author presents the views of various authors on this subject. In order to determine and compare the qualities of some of the materials recommended by literature as a covering for the paintings' reverse sides, studies were carried out of the influence of humidity and temperature changes on the canvas and the paint layer. The obtained results confirm the weight and influence of the base on which the painting is hanging, the microclimate behind the painting, at the same time confirming the great influence of the base on the course of the damage process. Materials that are excessively hygroscopic (soft cardboard, fibreboard etc.) should be considered very dangerous regardless of whether they are used as a covering, or constitute the construction on which the paintings are hanging (e.g. the divisions of exhibition rooms made ot tibreboard). The studies confirmed the unusual qualities of wood as covering material, known from preservation experience, old sources of information and contemporary literature. Wood not only levels out humidity changes, but also temperature changes, to a greater degree than any other material. Analysis of the literature, the results of studies on the qualities of the coverings and their influence on the formation of the microclimate behind the painting, the results of studies of many paintings and the author's own experiences have led her to conclusions that can be applied to preservation practices. These deal with the influence of the painting's surroundings - such as the humidity and the temperature - on the damaging of the painting structure. They also deal with the use of the coverings of the reverse sides as a method to counteract these damages.