I primarily use copper. When I do knapping demos, occasionally someone will suggest that's not the way the old guys did it and I will tell them about native copper and the evidence that it was, in fact, at least sometimes, used by native peoples. That always surprises them. Then, I tell them that the chances are slim it was widely used for knapping because of it relative rarity, explain that I use it for convenience and break out my hammer stone and antler tine and do a little percussion and pressure work to demonstrate I could be doing it that way if I didn't have copper. (When I first learned to knap it was a hybrid affair with hammer stones for percussion and copper for pressure and I maintain complete tool sets of both Abo and modern.) Back to copper in an Abo tool set: Even where copper was relatively abundant it was still a rare commodity and, like gold today, was apparently used for ornamentation and ceremony far more than than for utilitarian purposes. Additionally, the evidence that it might have been used as a knapping tool comes from quite recent times; only dating from perhaps 600-800 years ago, as far as I know, so that leaves out the majority of point types you could even pretend it was a possible Abo tool type. In another thread, I cited gold's use today as an analogy for copper use in the past and I suggested that gold could easily be used for tools but you still weren't going to find any at the local hardware store. That's a bad analogy (gold would be a poor choice for tool metal regardless of how much was around) and I'm surprised no one took me to task on it. A better example would be gold flatware. They make it and it's even readily available if you want to lay out the cash, but I'll bet you don't have any; not even gold plated. I'll bet your neighbors don't have any either. Copper was available, as gold is today, but rocks and other percussors were much more easily obtained and certainly less valuable. A whole lot more archeological evidence will need to come to light before copper heads will be able to claim they are knapping "Abo".