This thing isn’t specifically military grade but I suppose it could stop a slow-moving playing card flung at your chest. This cheeky little pocket square is called the “The Bullet-proof Handkerchief For the Promiscuous Idealist whom Lives in Elegant Danger”
The 21st century ninja dandy bullet-proof handkerchief made of Kevlar is exclusively sold at Liborius. The store and designer take NO responsibility for schmucks and wooden-heads who feel compelled to test the endurance or resistance of the textile in any way.
So there you go. It seems that this actually more of an art project than a real device but they’re actually for sale, so get cracking.