During WW2, MI5 came up with the idea of printing escape maps onto silk. As we know it can be folded up so small and when opened up, makes no noise whatsoever! At this time only John Waddington Ltd. had perfected the art of printing onto silk and these maps could be folded so small they could actually fit inside a Monopoly playing piece. And Waddington’s were also the UK licensee for Monopoly! These game sets were allowed to be part of ‘Care packages’ despatched by the International Red Cross to POWs.
And of the estimated 35,000 Allied POWs who escaped perhaps as many as a third were helped by their silk maps, either sewn into their uniforms or hidden away in a rigged Monopoly game.