Sheets of 20 first-class postage stamps featuring the two-color ASA centennial logo are now available in very limited quantities. Each of these self-adhesive stamps is equal to U.S. Postal Service-approved first-class postage (37 cents). Click here to order. The stamps are $12 for each sheet of 20 37-cent first-class stamps. The cost includes shipping, handling, and the cost of producing and authorizing the custom stamp design.