The first polyester fibers were produced by reacting ethylene glycol and either terephthalic acid or one of its esters to give poly(ethylene terephthalate). This polymer is still used to make thin films (Mylar) and textile fibers (Dacron and Fortrel).
This stamp also may be used for mailing items weighing up to 2-ounces. These Forever stamps will always be equal in value to the applicable price for the price category printed on them, at the time of use. The initial price and value for this stamp is 71 cents, effective May 31.
The face value is primarily 37 cents. Most used US postage stamps are worth 15 or 20 cents, the minimum amount required to catalog and stock the stamps. A number of stamps iâ¦ssued in 2002 have a bit higher values.