I take manila folders and cut them to fit in a binder for easy storage. Then I cut another one into the size I want for the "pocket". I glue the bottom of the "pocket" down (I've also used double sided tape). Once I have both front and back done, I use masking tape to bind the two pages together. I then use a paper punch to put it in a binder. You can purchase them from teacher supply stores, I'm just not willing to pay those prices.
On a side note, I typically use used manila folders that would normally go in the trash bin...or have here at the office and I've dug them out to use them. Hope this helps?
Could you tell me how you created the folders?