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.
A forever stamp is a stamp that is valued (sold and cancelled) at the current local letter rate of postage. For example, if the current cost of local postage is 50 cent â¦ s, the forever stamp is valued at 50 cents. If the price of postage rises (or miraculously, falls) the value of the forever stamp would be the new value. The forever stamp is forever valued at that rate. So, before the price goes up, buy a lot of forever stamps and you will save money. Forever stamps also save having to use 1 or 2 cent stamps to cover the postage increase. Saves you and the post office time and money.