I hope I am not stepping on any toes.
I had a chunky obsidian stemmed point that I was not happy with.
I saw a video Jack has on the web using a technique for thinning bifaces.
I thought It wouldn't help much on obsidian as it pressure flakes pretty good.
I also became aware of some other very good knappers using this technique
when I was in Florida this winter.
Well, I thought I would give it a try.