Shortly after entering World War II, the United States military found that shipping and delivering immense volumes of mail to and from servicemen overseas would be a challenge, especially given the need to reserve cargo space for critical weapons and supplies.
The solution, based on the British Airgraph Service, was called Victory Mail — V-Mail for short.
The Eastman Kodak-designed service launched on June 15, 1942 and became the primary method of communication between soldiers on the front lines and family at home.
A V-mail letter would be written on a piece of standardized stationery, then photographed and transferred onto a roll of microfilm. Upon reaching its destination, the letter would be blown back up to a readable size and printed.
Each letter passed before censors before being photographed, and the process foiled the potential use of espionage tools such as invisible ink and microprinting.
Using the V-Mail process, 1,600 letters could be crammed onto a roll of film the size of a pack of cigarettes. 2,000 pounds of cargo became 20, and 37 mail bags became just one.