What case did you get from Walmart?
It was in the section for homemade jewelry. It's a big hobby for women now. Next to the farbics in my walmart. It is advertised as holding 12x12 papers.
I would really like to know how you did it, it looks really nice! Great job!
Basically just get some foamboard and start cutting. I made the tray 9x12 so that I would have 3 inches for the cards. I then just lined the dice up in rows how I wanted them to fit and started drawing/cutting foamboard. When you cut the walls for each column, make sure they are shorter than the dice so you are able to grab them easily. The glue I used was Elmer's Probond. It tacks up quickly and dries strong and clear.