These are parts for my wallet design, which I'm working on with Christy Holzer. On the bottom left is my personal wallet, which I carry daily. On the top left are natural, vegetable-tanned leather parts. On the right are those same parts after being tanned (naturally, in the sun) and lightly oiled with Neatsfoot oil.
The tanned & oiled parts will be sewn up (by hand, by yours truly) tomorrow. I may switch over to one of these (be your own beta tester; eat your own dogfood), and will give the second to a friend.
Then I'll be tanning, oiling & sewing a small batch (with Christy) and hope to be putting them up for sale (and/or crowdfunding) soon.