People at GXL Titan (2015) might remember the guy selling mouse pads and t-shirts at the front of the venue. I checked today while looking the company up for a friend, and they've got an online store set up on their site now.
http://www.slothesports.com/slothmatpro/
I bought the large, and don't regret it at all. It's a well-made mouse pad that has a smooth surface and threaded edges. Some people I've heard describe it as similar to the Qck Heavy. Anyway, great quality, stitched around the edges (All sizes except the medium), I would highly recommend them.