1944-1pxB, 1944 U.S. National Christmas Seals, Imperforate Proof Sheet, pm "E", F, No Gum. Issued 1944 by the National Tuberculosis Association (NTA). Designed by Spence Wildey. Image of postman in the snow. Firm paper, fresh, never folded, shipped flat.
Sheet of 100 (10x10) seals. Colors: yellow, gray, red, and blue. Seal Size: 18x24mm. Printed by the Eureka Specialty Printing Co.
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.