Here's another 12-slot folding wallet. Here you can see the pieces as they are now. I make notches so that the slots will align perfectly. Also so that I can get the upper thread, which is more attractive, onto the outside of the wallet. You can see on this wallet there's one seam that's a bobbin seam, not so attractive.
The other thing that occurred to me is that I can put card slots into other jobs that have extra space. So I can accumulate a bunch of slots in different colors as I am doing other jobs.
I work with recycled billboard vinyl advertising tarps. Those products are for sale available at http://www.vinally.ca/ I also sell at http://www.etsy.com/shop/VinAlly
I live in Calgary Alberta. I worked for 12 years in the oilpatch as a geologist/database analyst. I also have a Certificate in Visual Design from the University of Calgary. I also paint and draw cartoons on the iPad. Vinally2010 on Flickr.