© Copyright 1995-2017, Clay Irving <clay@panix.com>

Paper Money Sleeves and Holders

I always use Polyethylene Terephthalate (PET) sleeves — Some people call PET "Mylar", but Mylar is a brand name of a special type of PET, Biaxially-oriented polyethylene terephthalate (boPET). The brand name I use is SafGard, from E&T Kointainer Company, the same folks who make KoinTains and SaFlips. I store the sleeved notes in red currency boxes available from many suppliers.

These materials in the table below have been classified as fine for archival storage.

[ Last Update: Wednesday, 18-Sep-2013 16:11:14 EDT ]

MaterialDescriptionExamples
PolyesterPolyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate (PET).SuperSafe or holders made from Profar Polyester
Polyethylene (food grade)This includes Polyethylene Terephthalate (PET), and "Mylar" or other biaxially-oriented polyethylene terephthalate polymers. Amorphous Polyethylene Terephthalate, or APET, is transparent version of the polymer — The semi-crystalline version is opaque and white and is commonly used in food storage. Melinex 516 is an example of a Polyethylene Terephthalate (PET) film.SafGard. Frame-A-Coin Currency Holders, PCGS Currency Holders, Lighthouse GRANDE and VARIO currency pages are "Mylar D" equivalent (See: PCGS Currency Holders "Take the Heat")
PolystyrenePolystyrene is an aromatic polymer made from the aromatic monomer styrene, a liquid hydrocarbon that is commercially manufactured from petroleum by the chemical industry. Polystyrene is one of the most widely used kinds of plastic.BCW Currency Slabs
PolypropylenePolypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles (e.g. ropes, thermal underwear and carpets), stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes. An addition polymer made from the monomer propylene, it is rugged and unusually resistant to many chemical solvents, bases and acids.UltraPro Banknote Holding Ring Binder Display Pages, BCW Polypropylene Pages
PlexiglasPlexiglas is a trade name for Poly(methyl methacrylate) (PMMA). It is sold under many trade names, including Policril, Plexiglas, Gavrieli, Vitroflex, Limacryl, R-Cast, Per-Clax, Perspex, Plazcryl, Acrylex, Acrylite, Acrylplast, Altuglas, Polycast, Oroglass, Optix and Lucite and is commonly called acrylic glass, simply acrylic, perspex or plexiglas. So, "hard acrylic" holders should be ok.Collector Safe, Capital Plastics Currency Holders, Image Guard Currency Holders
Barex®Barex resins belong to a family of acrylonitrile-methyl acrylate copolymers (AMAB) and offer high barrier properties to gases such as oxygen and nitrogen, as well as outstanding chemical resistance and inertness.PMG Holders

I would be suspicious of anything generically called "plastic", "acetate", "vinyl", or "PVC" (even if the PVC contains no plasticizers or stearates) holders. Sometimes, though, with a little research, you may find the "hard plastic" currency holder is made of acrylic or polystyrene, which should be fine.

The Library of Congress Preservation Web site indicates:


Update on Acceptance of Polyester Film Products for Use in Encapsulation of Paper Artifacts
(Revised October 22, 2004)

Over the past several months, we have tested several biaxially oriented polyethylene terephthalate (PET) polyester films and found them to be satisfactory for use in encapsulation of paper artifacts. The acceptable films are:

  • DuPont Teijin Films Melinex® film types 455, 456, 515, 516, made by DuPont Teijin Films (see http://www.dupontteijinfilms.com/ for international distributors)
  • DuPont Teijin Films Mylar® type LJP181 and KL, made by DuPont Teijin Films (see http://www.dupontteijinfilms.com/ for international distributors)
  • DuPont Hongji Films Type 8511 and Melinex®516, made by DuPont Hongji Films Foshan Co. Ltd., China
  • Hostaphan® 43SM film, made by Mitsubishi Polyester Film, LLC, of Greer, SC 29652.
  • SKC Inc.'s films SH71S®, SKC SH72S® and SKC SH18S®. These films are available from a number of distributors.
  • Tairlin CH28® film, manufactured by Nan Ya Plastics Corporation, Taipei, Taiwan, and available from Granwell Products, Inc., 185 Fairfield Avenue, West Caldwell, NJ 07039.

To the best of our knowledge, all of the tested films, with the exception of Melinex type KL and type KM films, are coated for slip on one or both sides for ease of handling. The two uncoated films are available in very small thicknesses, 92 gauge for Melinex® type KL and 48-200 gauge for type KM, which conservators may find limiting for many applications (100 gauge equals approximately 1 mil or one thousandth of an inch). While we would generally prefer uncoated stock to eliminate any chance of an unforeseen interaction with the artifacts being encapsulated, we do realize that most processors find slip coating to be essential for ease of handling. Moreover, most such coatings are highly stable.

Vendor Notes