portfolio box

I have recently been exploring Martine's idea of the "portfolio box" and matting all my pieces to place into it. Here are examples of a few that seem to work well. Some open like a book and all your pieces sit inside. And the third one down is really interesting to me but it seems a bit large. I am not sure exactly what I am looking for and have not really seen a ton of sites that allow you to buy them but I will definitely keep looking around. But if you guys seen any unique boxes definitely post them!!!!!