Pressure flaking involved pressing a section of bone or antler against the platform edge and increasing the pressure until the crack initiated and a flake was removed. The stoneworker could be very precise in the location where they set the tool and the direction of applied force.
The pressure flaking technique involved static loading of force onto the platform, in contrast to the dynamic loading seen in direct and indirect percussion. Static loading resulted in a more stable crack path. The pressure technique was usually applied by using the muscles and weight of the body to build up sufficient force for the flake to initiate. It was possible to achieve very precise and aesthetically-pleasing effects using pressure flaking.
In making bifacial tools, Native Americans held the core (a flake or biface) in the palm of their non-dominant hand and applied pressure with the flaker held in their dominant hand. In Australia, flintknappers held the biface in their fingers with one edge supported on an anvil. Pressure blade-making was achieved using a variety of complex techniques. The pressure-flaking technique was used on fine-grained stones.