For the transparent protection of manuscripts, comics, prints and drawings, maps, charts, photographic prints, posters, wallpaper and works of art on paper.

For the transparent protection of manuscripts, comics, prints and drawings, maps, charts, photographic prints, posters, wallpaper and works of art on paper.

Chalk, charcoal and art mediums/text with poorly fixed surfaces (this may include some damaged photo-images) should not be protected directly by any Polyester Films

The use of Polyester is preferred by many curators because it allows visual access without requiring physical handling of the photograph or artefact. Polyester is an exceptional material but only in products which avoid certain issues. Inserting and removing film continues to require a design which permits free passage, to avoid scratching and abrasion. Polyester enclosed films must be stored in an area with reasonable climate control to avoid the possibility of ferrotyping. Ferrotyping is the result of condensation and can occur when fluctuating relative humidity exceeds 65%. Stable high humidity generally will not cause condensation, so in using polyester for this purpose monitor changes at the higher levels.

The frosting or matt finish on certain polyesters is an inorganic physical abrasive permanently embedded into the surface which will abrade both film base and emulsion. This type of material should only be used if single sided . The matt surface should be on the outside of any storage pocket and must not be in contact with the negative or print.

Melinex Type O, Mylar Type D or Melinex Type 516

• These three polyesters are considered the safest of all archival plastics for film enclosures
• Melinex Type O and Mylar Type D are recommended for use where static qualities are preferred
• Melinex Type 516 benefits from a good slip characteristic providing less static with less likelihood of blocking in severe conditions. It has also been found to provide enhanced sealing properties using ultra-sonic means.
  
• Melinex O, Melinex 516 and Mylar Type D are available in cut sheets and are suitable for welding using the B-20 Polyweld Machine, the Criss Cross Welder and Ultra Sonic Welders.
  
• Melinex Type O and Melinex Type 516 are also available in rolls
  

Other plastics can be safe but should be accompanied by detailed specifications and established test results to ensure that high quality virgin material is used in their manufacture.