In 1963, Henry Jehan was a high school student taking classes in physics when he learned of an experiment being run by the Department of the Post Office. They were printing stamps with a special ink that would glow under specific frequencies of ultraviolet light. He saw this as a perfect melding of his studies and his hobby, sparking his lifetime interest in the luminescent tagging of postage stamps from their very beginning.
Jon the American Philatelic Society together with Henry Jehan as they review the development of the tagging process, along with a survey of the tagged issues (both regular and airmail) that have appeared on U.S. first day covers. Illustrations include items photographed under ultraviolet light.