Determining the meaning of the work prior to conservation is the foundation for responsible decision making in the conservation of modern art. The meaning of a work, however, is layered and certainly not unambiguous. One can speak of meaning imparted by the artist, but also by a context (criticism, group, style, time), by a place (collection, country, 'site-specific'), or event (performance). In addition, the choice of material and working method has consequences for the meaning of the work. Finally there are also ideological (political, philosophical and religious) layers of meaning. Hummelen, 1999, p. 167