Before beginning to preserve theatre materials it is essential to decide on priorities. Categories are proposed as follows: material of informational, but not artifactual, value (e.g. Newspaper clippings); material of artifactual value, but not unique (e.g. 1st editions, playbills, posters, photographs); material that is unique (e.g. Manuscripts, letters, some scrapbooks); historic artifacts of little informational value (e.g. Costumes, props, autographs); fine art material (e.g. Original drawings for sets, costumes, etc.) the next phase is to decide on conservation priorities. Suggested categories include: very urgent (i.e. Material liable to disintegrate - brittle paper, or mould damaged); serious (could survive if put into better housing, and not put on exhibition); treatment needed for long-term preservation (such as dry cleaning, repair, deacidification); and good condition (needing nothing except possibly cosmetic treatment for exhibition purposes). -- ICCROM