Presence', in its dual significance of immediacy and of being in a particular place at a particular time, has become the major theme in recent performance practice and theory. The intense interest in the status of the documentation of performances - be they photographs or films - set in motion a search for new means of immediacy, but also a scepticism concerning the existence of authentic presence. Performance scholars focus on the document more self-consciously to trace performance art back to object-based art practices, such as action painting, and the polemics of a post-Second World War art world discursively severed from the classic European avant-garde. Documentation has been the 'faithful' companion of performance since the grainy image of Hugo Ball reciting his poetry in Marcel Janko's cardboard costume and it has turned up in gallery exhibitions as well as on the art market since the 1960s.