I ordered some air mail envelopes and gummed air mail labels from a supplier via Amazon, paying exorbitant and completely unnecessary shipping costs. But I knew I wanted to do some sort of mail art project with them, so I braced myself for the higher price. (My local Staples and Office Depot don't carry these evelopes, but I have since found them at a great store called Deals in the nearby town of Media for much less than what I paid .)
Step 1: First, I folded the air mail envelope in half.
I used red thread to match my colors. I made the inside my "clean" side, and the outside my "messy" side, with all of my thread ends and such. I'm sure this part could be hand stitched as well.
Step 7. Next you can add whatever you like to your book cover, preferably keeping with the air mail theme. I chose to keep it simple and clean with a label, a small piece of paper tape, and a foreign stamp. You could add rubber stamping, cancellations, drawings, stickers--whatever suits your aesthetic. You can do the same to the back of the little jotter notebook, but I chose to leave mine plain.