Conservative and also preventive measures merely serve to maintain the substance of a work of art. In contrast, the goal of restoration measures is to return the damaged work as closely as possible to its original state and to make its appearance and its expression perceptible again. Experience shows that the first imperative should always be to limit treatment to that which is absolutely necessary because works of art are at risk not only from omitted measures but also by inappropriate measures. Moreover, both the consideration of the procedure as well as the choice of the materials used to treat the work of art should be made strictly from the perspective of reversibility.