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.
First Class is currently worth 42c. Forever Stamp is worth First Class, even if it's value increases. Older First Class Stamps are worth what they were worth.(The current First Class Stamp has a flag and clouds) The USPS is usually lenient on a few cents, so the older First Class stamps are usually counted as being worth 42c. The current rate of postage, mailing from US to another US adress, is 42c.(First Class Rate).The current First Class Stamp has a flag and clouds) The USPS is usually lenient on a few cents, so the older First Class stamps are usually counted as being worth 42c. The current rate of postage, mailing from US to another US adress, is 42c. (First Class Rate).