Mylar

A registered trademark for a series of optically clear, colorless, thermoplastic polyester films. First introduced in the early 1950s, Mylar® is composed of polyethylene terephthalate. It is a biaxially oriented film that is chemically inert and dimensionally stable. Mylar is an effective barrier to moisture, oil and grease. It has been used for lamination, coating, embossing, printing, and dyeing. Mylar has been also used for heat seal packaging. Mylar® type D sheets are uncoated and have been used for enclosing photographs and coins as well as for making photocorners.
Note: Mylar® type D sheets were discontinued September 2001 by DuPont.