Here's the mat I made. It's attached to the case and rolls up into itself. It's 500D to be a little lighter and has a yoga mat sewn into the upper half for a bit of cushioning. I added a strap for the bipod legs to help in keep it from slipping. I have no idea if that actually works yet, I haven't tested it... I put a whole bunch of webbing on the case for multiple ways to attach to my ruck, depending on where it'll fit.