With a 1942 release date, Casablanca appeared in cinemas in the middle of World War 2. Due to paper rationing at the time, it was not uncommon for film posters to be printed on paper that had already been used for a different purpose. This particular poster was printed on the reverse of a map: Belgium's south-western borders with France and Germany. The map can be seen through the poster when it is held up to the light.