Beginning in the Solutrean, a complex technique of stone preparation was developed. Known as heat treatment, this process involved "cooking" large pieces of flint for fairly long periods. The result was a raw material with a porcelain-like sheen. The development of heat treatment in the Solutrean seems to have coincided with a means of working flint, known as "pressure flaking," by which the tool-maker forced flakes off a piece of flint by exerting pressure with a "flaker" made from reindeer antler or hardwood. Many of the fine Solutrean leaf-shaped points such as the one shown here were produced in this fashion.