Problem with any kind of binder is that some of them you have to Equip, so you'll be having to pull certain cards out from time to time and them putting them back in.
A card sleeved with an FFG standard card game sleeve fits nicely into a page of the Zatchbell spell book. The FFG sleeve is about 3mm taller than the page making the card easy to remove.
I did the same. I think MM still has a few left you can buy online. They don't stay open very well so I modified mine with some rare earth magnets and straps. they work very well. I'll try to get some pics up if I can.
Sounds pretty sweet! Pictures would be appreciated!
Smart idea. I'm also very interested in seeing exactly how you did it.