I think I would have starved if I was a native a many hundred years ago , I Tried a glass jar bottom , a thinner glass bottom , a piece of orange chert , then tried to re work an old thick flint scraper , and I just couldn't get any thing too shape . I was using abo tools it seemed to me that I wasn't able to get the thickness worked out of any of the pieces . guess im gonna have to find a knappn somewere in OHIO to set in on.