Let's make a simple, cheap, durable bifold wallet out of Tyvek (the housing wrap and express mail envelope material).

Please note: this is my first instructable.

Step 1: Materials and Pattern

Materials: 6 x 14.5 inches Tyvek or fabric of your choice (duct tape, 1000 denier nylon, denim, rip-stop nylon, etc), 3 inches of elastic (almost anything will work), optional: zipper, velcro

You can either sew the wallet together (which I am doing), or tape it together with packing tape or duct tape or another suitable tape.

This is the pattern, all measurements in inches. No seam allowances are needed.

If this image is unreadable:
the main body is 6 x 7.5
the small flap is 0.75 x 2.5
the large flap is 2.5 x 4.5

Step 2: Construction Step 1: Cut Out Pattern

Place the above pattern on the right side (the side you want showing) of the fabric.

Cut out the perimeter. Do not cut the flaps off.

Step 3: Construction Step 2: Attach Elastic Band

Sew (or tape) the middle of the elastic to the skinny flap. This is going to be the card holder. OPTIONAL: sew velcro to the flap to keep the wallet closed.

Fold the flap along the dotted line (about 1/4 inch from the body of the wallet, depending on how many cards you carry) and sew the elastic to the body at the top and bottom of the elastic.

Step 4: Construction Step 3: Change Pocket

Fold the larger flap over. This is going to be the change pocket. This flap seems too long (it goes past the halfway point) because we are going to make accordion folds so that it expands when we put things in it. OPTIONAL: sew velcro to the flap to keep the wallet closed.

Make accordion folds at both sides of the flap. Sew them up. Finally, sew the bottom (you may not want to sew over the accordion folds - I did). The pocket is now complete. OPTIONAL: add a zipper to the top of it.