18-1x, WX21, 1918 U.S. Red Cross Christmas Seals Sheet - WANTED.
To avoid competition with other fund drives in progress during World War I, the regular seal sale was suspended. Everyone joining the Red Cross Roll Call was given one or more panes of ten (10) seals. It is not known if any sheets of 100 seals were issued, and all sheets should perhaps be considered essays.
Green's Catalog, Part 1, U.S. National Christmas Seals, pg.18.