Waddington PLC, the printing company best known for its games including Monopoly, was involved in a most unusual venture during the Second World War: printing maps on silk, rayon and tissue paper for military use and smuggling some of them to prisoners of war.
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During WWII hundreds of thousands of maps were produced by the British on thin cloth and tissue paper. The idea was that a serviceman captured or shot down behind enemy lines should have a map to help him find his way to safety if he escaped or, better still, evade capture in the first place. A map like this could be concealed in a small place (a cigarette packet or the hollow heel of a flying boot), did not rustle suspiciously if the captive was searched and, in the case of maps on cloth or mulberry leaf paper, could survive wear and tear and even immersion in water. The scheme was soon extended to cover those who had already been captured, although a certain amount of ingenuity was required to get the maps into the POW camps.
Link - via holeinthedonut
From the Upcoming ueue, submitted by baweibel.