52-1x2, WX159, 1952 U.S. Christmas Seals Sheet, pm E, with Union Label, full gum, F, MNH. Issued 1952 by the National Tuberculosis Association (NTA). Designed by Thomas Darling. Image of a candle and double-barred cross, Fresh, full gum, never folded, shipped flat. Scan is of a full sheet.
Sheet of 100 (10x10), yellow, black, red and green. Seal size: 171/2x231/2mm. Printer's Mark: "E" on the green background, between the candlestick and its tray, in lower right corner of seal #56. With Union Label.
Note: Sheets of 1952 Christmas Seals were printed by 5 printers. They can be identified by a tiny black "E, S, D, U, or F" on seal #56.
Marginal inscription at bottom of sheet: "Chest X-Rays Find Tuberculosis Early When It's Easiest To Cure" with red double-barred cross at beginning and end of text. No Union Label.
Christmas Seals are also known as TB Charity Seals, and are usually classified as Charity Seals, or Cinderella Stamps.