Large libraries, art galleries and museums have considerable proportions of their collections in storage areas inaccessible to the general public due to the cost of display space, operating costs, and the need to adequately protect their holdings from damage or theft. As a result, ever smaller proportions of cultural heritage are actually suitably displayed to permit casual browsing, and in many libraries browsing is no longer possible. Each item must be specially requested on the basis of prior knowledge of its existence.
The insatiable appetite of museums for material has resulted in many hastily acquired collections without adequate documentation for each item's cultural or historical context. Not only are collections poorly accessible, they are not always well identified and catalogued, so that retrieval is doubly difficult. In the case of libraries, the lack of access is in part due to the flooding of the world by printed matter, most of it of an ephemeral nature. Books of little worth cause cultural pollution encrusting in libraries the books embodying the cultural heritage. Truly current general collections are no longer possible and libraries resort to dispersal and fragmentation in order to service specific groups of readers in limited subject areas.