Most anvils I have seen are made from stone, used under the point while pressure flaking to help flake terminations and to keep the work piece off the leather if you want long flake travel. Adjust it underneath in front or behind where you want your flake to term. It will absorb the flakes energy and stop the travel,or move it up a little to help increase it. (clear as mud)?
I use it on occasion when I need to run some across the face, or when I want a flake to stop at a certain place. It takes a bit of getting use to but it will work.
I had a stone one, but broke it in a few pieces one day so I decided to make me one from horn. This one is made from moose antler, and is already starting to show some wear .