I got a bunch of Tyvek scraps from misprints at work and thought I would do some projects with them. They are all poster sized but i cut them down to what i needed. If you cant find any sheets of Tyvek, lots of mailing envelopes are made of Tyvek and are free. Tyvek is a plastic product with the basic properties of paper. It is water resistant, and nearly tear proof.
Step 1: Cutting and folding
I got tired of folding up my paychecks and wanted a wallet big enough to hold them. Thats how i decided how large to make this wallet; big enough to fit the huge (not in amount, but sheer size. why are they so big? my checks are one third the size) checks I get.
I started with a piece of Tyvek 4 times the height of the check and a little wider. IT was about 10x14 inches. I folded the sheet in half then each of those in half as well. One fold will later house the cards, one the cash and receipts, and the "hidden compartment " on bottom would hold the checks.