# 1431a - 1971 8c Antarctic Treaty

U.S. #1431a Tagging Omitted
8¢ Antarctic Treaty

Issue Date: June 23, 1971
City: Washington, DC
Printed By: Bureau of Engraving and Printing
Printing Method: Giori Press
Perforations: 11
Color: Red and dark blue

This stamp was issued on the ten-year anniversary of the signing of the Antarctic Treaty - an agreement among twelve nations meant to foster scientific cooperation in the Antarctic region. It was hoped that this cooperation would lead to more peaceful uses of the Antarctic and its resources. The stamp design is adapted from an emblem used on official Consultative Meetings documents.

Now you can own this stamp with rare tagging omitted.  Did you know a stamp missing its phosphorescent tagging is considered by many to be similar to a missing color error? The good news is that unlike some error stamps, untagged error stamps are affordable.  

What is Phosphorescent Tagging and Why is it Important?

Tagging of U.S. stamps was introduced in 1963 with airmail stamp #C64a. It helps the U.S. Post Office use automation to move the mail at a lower cost. A virtually invisible phosphorescent material is applied either to stamp ink or paper, or to stamps after printing. This “taggant” causes each one to glow in shades of green (red on older airmails) for a moment after exposure to short-wave ultraviolet (UV) light. The afterglow makes it possible for facing-canceling machines to locate the stamp on the mail piece, and properly position it for automated cancellation and sorting.

Some stamps have been printed with and without tagging intentionally, but when tagging is omitted by accident, we collectors are treated to a scarce modern color error. Our stamp experts examined thousands of stamps to find these just for you. Now you can easily give your error collection a boost or explore this fascinating new area of collecting. Quantities are limited, so order your untagged error stamp right away.

And find more tagging omitted stamps here.