Maps are harder to smuggle than you might think. They fall apart when wet, and they make a lot of noise when unfolded. Allied officials feared paper maps might draw the attention of German troops, so they turned to an unlikely source for help — silk. Not only would silk maps hold up in all kinds of weather, but they’d also come with the life-saving benefit of being whisper quiet.

To produce these silent maps, the Brits turned to John Waddington Ltd., a company that had recently perfected the process of printing on silk and was already manufacturing silk escape maps for British airmen to carry. What else was Waddington known for? You guessed it — being the licensed manufacturer of Monopoly outside the United States.

[via CNN]