V-mail

[1][2] V-mail correspondence was on small letter sheets, 17.8 by 23.2 cm (7 by 9+1⁄8 in), that would go through mail censors before being photographed and transported as thumbnail-sized image in negative microfilm.

According to the National Postal Museum, "V-mail ensured that thousands of tons of shipping space could be reserved for war materials.

In addition to postal censorship, V-mail also deterred espionage communications by foiling the use of invisible ink, microdots, and microprinting, none of which would be reproduced in a photocopy.

In 1940, the British Minister of Transport, Lieutenant Colonel John Moore-Brabazon, 1st Baron Brabazon of Tara, put forward the idea that airgraphs be used to reduce both the bulk and weight of mail travelling between the Middle East Force (MEF) and the UK.

Although the airgraph proved to be immediately popular, its use was limited because of its size (approx; 11cm x 13cm; 4" x 5") and lack of privacy, so when sufficient aircraft capacity became available, its use declined in favour of the air letter.