There is now new 4 card slim wallet version 2 and a 6 card wallet. The new designs fit nicer in the pocket and have improved finger reliefs to get cards out.
I had a leather slim wallet that had a similar design but was falling apart. This wallet has been far better, cheaper and should last much longer. Also look pretty cool compared to the average leather wallet.
This is a work in progress and want to hear your thoughts, be sure to leave a comment if you have any suggestions.
The bottom tends to curl a bit so a clean hot bed is very important and it is a very good idea to use a brim and trim it off with a knife after printing.