I make lots of these with different fabrics. This one is heavyweight linen look ripstop Nylon outer, with lightweight ripstop inner. There's also aluminium foil in between the layers (which makes it a bit stiff, but I'm going to look into using Mylar). A brief test showed it effectively blocks RFID so should help prevent skimming attacks. I keep one on my car keys with a bank card, spare facemask and a pair of disposable gloves in it. Since the photos were taken, I've added a decorative lanyard to the zip tab (and trimmed off that loose thread end!). Label is a bit big (and sewn upside down as you can't see my logo/website on it) but I'm ordering some smaller ones