Restoration of bookbinding leather. The problem of materials selection

This article talks about the problems that bookbinding restorers face when choosing materials for preserving bookbinding leather. One of the most difficult tasks of bookbinding restoration is to restore the elasticity and flexible of the original leather cover. The author points out that the choice of restoration (conservation) technique depends on the state of preservation of the leather cover, the peculiarities of the material itself and its treatment in the past, its use and storage conditions. Chemical reactions occurring in the material over time under the influence of external agents, lead to the destruction of the leather covering may not be reversible. In the article the basic reasons of destruction of leather are stated, the agents which render negative influence on its state of preservation are resulted. The study of mechanisms of leather destruction showed that the use of lubricants for its plasticization can have a negative impact on the state of preservation in the future. But even when softening compositions are used, it is not always possible to achieve a positive result. The author concludes that the use of combined methods for plasticizing is effective when working with leather which has lost its elastic properties in the process of being in the book. Such a technique, including remote moistening of the leather and treatment with lubricants, was used for the restoration of the leather binding of a 15th century book which was severely damaged in the course of its life. At present the Department of Scientific Restoration of Manuscripts of the State Research Institute for Restoration is working on the study of the possibility of using lecithin for leather restoration. The peculiarities of lecithin structure make it a good moisturizing surface-active material. It is known that in the late 80's of the 20th century lecithin restored the blistered leather of a 17th century carriage.