I'm finishing up work for an art show next weekend. For the first time, I've made some 16x20 prints. They came out well, and I'd like to take them to the show. When it comes to mounting and presentation, 8x10s and 11x14s are easy. There are generic sized window mats, mount boards, and bags for these sizes. When you get to 16x20, nothing is generic anymore. I'm not sure what size board to mount them to. I've thought about mounting them onto a 20x24 board, but that doesn't seem to be a common frame size. 22x28 is much more common. It seems that staying with an off-the-shelf frame size would be wise, but maybe not. Ideas? Experiences?