The two techniques of making stone tools were: (i) Stone on stone technique. In this technique, the pebble from which the tool was to be made was held in one hand. Another stone, which was used as a hammer was held in the other hand. The second stone was used to strike off flakes from the first, till the required shape was obtained. (ii) Pressure flaking. In this technique, the pebble or core was placed on a firm surface. The hammer stone was used on a piece of bone or stone that was placed on the core, to remove flakes that could be shaped into tools.