Pressure Flaking
When pressure flaking, a knapper uses a point of bone, antler, or copper to remove small flakes. The knapper pushes the pressure flaker's point directly into the edge of the tool where a desired flake is to be removed. As the knapper increases the pressure into the tool, he or she changes the direction of the force to a downward motion, snapping off a small removal. Pressure flaking is best for detailed shaping of tools and making sharper and delicate tools. This technique is used to retouch tools and also make the characteristic notches of small arrow heads. Pressure flakes are typically small compared to hard or soft hammer removals but with practice they can be made long enough to thin portions of a tool.