The Overrun Countries issue honored the countries occupied by the Axis powers during World War II. Furthermore, issuance of this series of stamps implied the free world's determination to liberate these countries. For the first time since 1893, the Bureau of Engraving and Printing contracted with a private firm so the stamps could be printed in colors. The American Bank Note Company was the contractor. Frames of all of the stamps of this set are produced in a slate-violet color. The center of each stamp was printed by a different production method in the colors of the flags. Very little production information on this set was ever made public.