An Upper Paleolithic technique for making blade flakes. After first preparing a rock core, a hard pointed punch (usually made from a deer antler tip) is placed near the edge of a striking platform and a percussion blow with a hammer to the top of the punch sends a controlled shock wave into the core which removes a thin, narrow blade flake. Upper Paleolithic cores prepared for this technique were usually conical or cylindrical in shape with a relatively flat perpendicular striking platform at one end.