1960-2x, WX207, 1960 U.S. National Christmas Seals, Sheet, pm D, full gum, F, MNH. Fresh, never folded, shipped flat. Scan is of a full sheet.
Issued 1960 by the National Tuberculosis Association. Designed by Philip Richard Costigan. Four seal designs of choirboys and girls alternate in the sheet, creating se-tenant blocks of 4. Sheet of 100 (10x10) seals, with vertical perfs running through margin. Margin at top inscribed, "Christmas Seals Help Protect The Family Circle". Colors: tan, black, green, and red. Seal size: 16x21mm. Perf is 11. Printer's Mark: "D" on seal #56, between the two carolers. Union label in margin above seal #10.
Christmas Seals are also known as TB Charity Seals, and are usually classified as Charity Seals, or Cinderella Stamps.