Remixed to hold a rolled-up MTG playmat, and to print without supports. I also sliced a cylinder out of the center, to make a smoother inner-surface to slide the mat into.
It is very tall, and I had to use my Tevo Tornado to print it. You could always slice it in Microsoft 3D Builder and make a shorter version, if you don't mind part of the mat sticking out the end (or try to print it in two parts). I don't recommend simply resizing it to make it smaller, because you may end up needing supports inside the structure.
I used 3 shells and no infill. I also used a brim to help stabilize it while it printed.