Global Forever international U.S. Postage Stamps Sheet of 10 Stamps Global Forever stamp can be used to mail a one-ounce letter to any country to which First-Class Mail International service is available This Global Forever stamp can be used to mail a one-ounce letter to any country to which First-Class Mail International service is available. ISSUED at the $1.20 price, this Global Forever stamp can be used to mail a one-ounce letter to any country to which First-Class Mail International service is available. Sheet of 10 GLOBAL Forever U.S. Postage Stamps 2016 the shape of the international stamp is round and bears the words Global Forever.