Archival Polyester Sheets are perfect for the transparent protection of manuscripts, comics, prints, drawings, maps, charts, photographic prints, posters, wallpaper and works of art on paper. Many custodians prefer polyester for film enclosures because it allows visual access without requiring physical handling of the artefact. To avoid scratching and abrasion whilst inserting and removing film, this design permits free passage. Polyester enclosed films must be stored in an area with monitored environmental control to avoid the possibility of ferrotyping. A result of condensation ferrotyping can occur when fluctuating relative humidity exceeds 65%. The frosting or matte finish on certain polyesters is an inorganic physical abrasive permanently embedded into the surface which will abrade both film base and emulsion. We agree with conservators from the world’s major archival repositories that only three polyesters, each meeting a rigid set of specifications, should be considered to be true archival plastics. Type ‘0’ is ideal for use where static qualities are desired. Chalk, charcoal and art mediums/text with poorly fixed surfaces should not be protected directly by any polyester films.