We certify that all pouches are made from film that adheres to the
Library of Congress Spec. 500-500, “Polyester Film for the Storage of Artifacts”. Our films also meet the requirements of the “Photographic Activity Test” (PAT), ISO 18916.
Dimensions can vary from very small (1" x 1"), to large sizes
(up to 61” wide with unlimited lengths).
We generally use 3, or 4 mil polyester for our heat sealed products.
Regarding film thickness: Our pouches are made with a film thickness of
3 mil or 4 mil (75 or 100 micron).
Here is a comparison of 3 mil vs. 4 mil film: 3 mil (0.003 inches thick) is thinner than 4 mil (0.004 inches) film. The pouch consists of 2 layers of film, heat sealed along the outside edge. In terms of rigidity, one layer of 3 mil film is comparable in rigidity to a piece of paper from your printer.
4 mil is more rigid. Some customers prefer 4 mil for use in exhibits or in any application where the item will be frequently handled. The 3 mil is more suitable for storing documents. Also, the 3 mil is less bulky than the 4 mil. You can place more pages into a binder or box using the 3 mil version.
Standard Styles (Please see our "Specifications" page for illustrations.)
Our sleeves can be heat sealed on any of the sides, sealed on one side, two sides, or three sides.
A "Folder" can have a heat seal along one long edge, or along one short edge.
An "L-seal" (or "L-weld" or "L-sleeve") has two heat seals (seals on 2 adjacent sides).
A "Sleeve can have 2 long sides heat sealed with the two short sides remaining open,
or 2 short sides heat sealed with 2 long sides remaining open.
The "U-seal" is the most common style which has heat seals on three sides.
It is open on one short side or one long side.
Additionally, we can provide individual polyester "cut sheets" in 1, 2, 3, 4, and 5 mil
available with optional tissue inserts.
We can also ship product in roll form.
Here are some other descriptive terms for our product:
Sheet Protector, Page Protector, Cover, Envelope, Exhibition Page, Enclosure, Protective Sleeve, mylar Sleeve, Polyester Sleeve