I decided a wanted a handy dandy wallet for carrying various small sizes of art paper--ATC size, 3.5 x 3.5 and 4x4, so I bought a sheet of Tyvek for $2 bucks, had it cut down, and started tangling. Once I covered one side of a 10x14 sheet (the finished sheet is the example I used for the tangle Intersect), I looked up an origami pattern online, and started folding. Too much of my zentangle was covered in the finished result, and lots of white showed, so I did some more tangling afterward. And here 'tis:

Inside wallet showing the pockets      Outside wallet showing pockets

 

Artwork outside wallet:

Artwork inside wallet:

I'm happy with the size and shape of the wallet, but the ink does leave a faint smudge on my fingers, and I'm enjoying the whole process.  I've got some more Tyvek, so I'm going to make more.  I'm painting an acrylic background before tangling this time.  We'll see if that helps make the ink less liable to wear.