Be careful storing it standing up at any sort of angle. I acquired a TFLE PF that was cleared and stored on end and it developed a slight warp to it. Was able to flatten it out by attaching straight boards to the back (like the rails when installed in a game) for a while before mounting it to my wall for storage.

Would love to hear Ron's advice on proper storage for those without a PF rack. Doesn't make a lot of sense to build one when you only have 1 or 2 PF's. I have all mine mounted to my wall in my office right now.