Unknown.
DCL
One sheet of letter-size paper and some sticky tape are all you need to fold together a seamless wallet that is the pinnacle of minimalist chic. This Instructable further impresses by supplying enough room for a wad of bills, as well as up to 8 credit cards. (You're on your own when it comes to loose change, however.)
Work your origami-fu on a used Tyvek mailer to guard your wallet against tears, rips, and water damage. ::Instructables
Difficulty level: Easy
