Restoration of works of art became an established practice from the 16th century onward with the creation of art collections and museums. Up to the 19th century, in context of the belief in an emotional approach to works of art, the restorer brought to his work the middle class tastes in art which had more to do with “appearance” than with “reality”. In the 20th century, the notion of a “cultural heritage” spread, bringing with it the notion both of the “real” and of the “useful”. The role of the restorer changes in the 20th century, the artistic approach combines with the scientific approach and so the method followed becomes that of restoring the process of creation of the object.