In 1941, an increasing number of British Airmen found themselves as the involuntary guests of the Third Reich, and the Crown was casting about for ways to facilitate their escape.
One of the most helpful aids is a map, showing where stuff is and locations of 'safe' houses where a POW on-the-lam could go for food and shelter.
Paper maps had drawbacks, they make a lot of noise when opening and folding, they wear out rapidly and when wet, turn into mush.
Someone in MI-5, got an idea of printing escape maps on silk. It's durable, can be scrunched-up into tiny wads, can be unfolded as many times as needed and makes no noise.
At that time, there was only one manufacturer in Great Britain that had perfected the technology of printing on silk, John Waddington, LTD. When approached by the government, the firm was only to happy to do its part for the war effort.
By pure coincidence, Waddington was also the U.K. Licensee for the popular American board game, Monopoly. As it happened, games and pastimes was a category of item qualified for insertion into 'CARE packages', dispatched by the International Red Cross to POW's.
Under the strictest of secrecy, in a securely guarded and inaccessible old workshop on the grounds of Waddinton's, a group of sworn-to-secrecy employees began a mass- producing escape maps, keyed to each region of Germany or Italy where Allied POW camps were regional system. When processed, these maps could be folded into such tiny dots that they would actually fit inside a Monopoly playing piece.
As long as they were at it, the clever workmen at Waddington's also managed to add:
1. A playing token, containing a small magnetic compass
2. A two-part metal file that could easily be screwed together
3.Useful amounts of genuine high-denomination German, Italian and French currency, hidden within the piles of Monopoly money
British and American air crews were advised, before taking off on their first mission, how to identify a 'rigged' Monopoly set -- by means of a tiny red dot, one cleverly rigged to look like an ordinary printing glitch, located in the corner of the 'Free Parking' square.
Of the estimated 35,000 POWS who escaped, an estimated one third were aided in their flight by the rigged Monopoly sets.
This information was declassified in 2007 when the surviving craftsmen from Waddington's, as well as the firm, were honored in a public ceremony.
I bet, after reading this, that when you play Monopoly, you'll never look at the 'Get Out Of Jail Free' card the same, I know I won't.