I bought this choker for 2 dollars. It's PU leather material apparently. I tried it on my test piece about 2 months ago. Obviously I should have documented that experiment when I did it, but I never did.
This is what the stain looks like now. Right when it was made, it was the most perfect stain I have ever seen. Now after some time has passed, the stain is still visible, but it's starting to fade out. However, the stain has sunk through the test piece quite a bit. I wonder if it will come out on the other side eventually?
So my conclusion is, avoid all black leather material on your TPE doll. Even if you put a body stocking in between your doll and the leather, it is still too risky. I would not recommend it. I will not include a link to where you can buy this. This thing will never touch my dolls.