Just the standard business sized envelope will do.
I like the self-adhesive ones, so I don't get a paper cut on my tongue :)
You want the envie open on both ends creating a tube (these will become the pockets).
DO NOT TRIM the third envie to 9" (see next step).
This ends up being 4 3/4". Save the other half for the next page you assemble.
note: Hold 1/2 envie so that opening is on right. Apply adhesive to right side and top, bottom, and left leaving a 5/8" margin on the left. This is where your album's binding will go.
Make top and right hand side of each piece flush. The tab for the binding should stick out on the left.
Flip unit created in step 9 over. Again don't put adhesive on the binding tab. Glue longer envie (one with 1- 1/2" folded pocket) to this piece making bottom edges flush.
This is what you should have when you are done:
And here are the measurements for cutting the papers to cover the pages:
I cut a little notch out of the top back pocket to access that pocket.
And before I covered the pockets with pretty papers, I did a quick swipe with the paint brush on the edges (or you could ink them).
Here's another look at my finished album:
If you have any questions at all, I am happy to answer them.