1937-3p1x, 1937 U.S. National Christmas Seals, Imperforate Proof Sheet, pm "D", F, No Gum. Issued 1937 by the National Tuberculosis Association (NTA). Designed by A. Robert Nelson. Image of Town Crier. Firm paper, fresh, never folded, shipped flat. Label is not attached to sheet.
Image of Town Crier on 96 regular seals with four slogan seals. Sheet of 100 (10x10) christmas Seals, 96 regular seals with four slogan seals. Seal colors: yellow, black, red and blue. Edward and Deutsch Lithography Co., there is a red dot on the lower right corner of seal #55, and a 'D" on 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.