USPS Global Stamps can be used to mail a 1 oz letter or postcard to any country to which USPS First-Class Mail International service is available. They are self-stick (peel and stick) for easy mailing. Forever stamps are valid even when the rates go up, so stock up now before the next rate increase. Each stamp has a face value equal to the current Global Stamp rate, so you can use multiple stamps or additional postage to cover your total shipping cost. Stamp Issuing Entity: USPS; Denominated (Yes or No): Yes; Stamp Denomination: Forever; Mail Service Type: International.