1936-4px, 1936 U.S. National Christmas Seals, Imperforate Proof Sheet, pm "U", F, No Gum. Issued 1936 by the National Tuberculosis Association (NTA). Designed by Walter I. Sasse. Image of Santa with candles, issued as a se-tenant pair. Firm paper, fresh, never folded, shipped flat. Label is not attached to sheet.
Sheet of 100 (10x10) Christmas Seals. There are 96 regular seals (48 se-tenant pairs) and four slogan seals. Seal colors: yellow, gray, red, and green. United States Printing and Lithograph Co., there is a green letter 'U" in the lower right corner of seal #56.
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.