1930-1pxA, 1930 U.S. National Christmas Seals, Imperforate Proof Sheet, full gum, F, pencil mark and smudge on back, NH. Fresh, firm paper vibrant colors, never folded, shipped flat.
Issued 1930 by the National Tuberculosis Association. Designed by John W. Evans. Image of Santa with tree. Colors: gray, red, and green. Sheet of 100 (10x10). Printers Mark: a green dot on the base of the "M" of Merry on seal #1.
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.