I just love these! They are a big help when you've got lots of birthdays to remember.
I take some "chipboard" that hubby brought home from work and cut it down to the directions here on SCS. I cover it with DP and mod podge, set it under a heavy book and let it dry overnight. The next day I add the inner pages and use my Bind it All to attach it all together.
I made quite a few of these at once so I'm sorry that I don't remember the exact paper used. I just hope that these inspire you to create something.