1966-5p2x, 1966 U.S. National Christmas Seals, Imperforate Proof Sheet/100 seals, dull gum, pm "B", F, NH. Fresh, firm paper, never folded, shipped flat. Scan is an example. Full scan of front and back available upon request.
Issued 1966 by the National Tuberculosis Association (NTA). Designed by Heidi Brandt. Four (4) different designs of birds in trees, in blocks iof four (4) alternating with white or green backgrounds. Printed by Berlin Lithography Company.
Imperforate sheets have no perforations or rouletting at all.
Christmas Seals are also known as TB Charity Seals, and are usually classified as Charity Seals, or Cinderella Stamps.