Since the practice of direct carving had been abandoned in the 19th century, the sculptor was above all a modeller. He searched for the first idea of his composition in clay. He made his study by working with balls or sticks of clay which he shaped with the help of his thumbs, sometimes leaving very visible imprints, like the incisions made by a knife or roughing-chisel to emphasize certain effects. The next step was a more accurate maquette or model, mounted on an inner armature, which had to be wrapped in a damp cloth between working sessions to keep the clay malleable. This is the great advantage of clay.
Nothing is easier than to change, remove or add to the material as required.
However, clay is very fragile until it is fired, and even then, only small studies can be fired without risk. As soon as the sculptor is satisfied with his model, he has an impression made. Since the initial model is nearly always destroyed during the casting operation, the plaster cast extracted from the mould is the first permanent shape of a work. This type of mould can used over and over again. The network of slender strips and seams visible on the surface of many plasters show where the various pieces of the mould were joined together.