Escape maps were used by the Allied Forces in WW2 and the Cold War when they needed to find their way home ! from behind enemy lines. They were sewn into clothing and being silk were strong and durable- and didn't disintegrate as a paper map would do.
Beautifully printed and issued by the War Office, these really were a useful textile item.
It begs the question of how many silk escape maps were made into knickers by forces wives and girlfriends !!!!!
I might just frame mine !!!