Final answer:
Lost-wax casting is an ancient sculpture technique where wax is used to create a negative space for molten metal, resulting in a unique work of art after the mold is broken and the metal piece is polished.
Step-by-step explanation:
The technique in question is known as lost-wax casting, which is a process used in sculpture creation. Lost-wax casting is an ancient method where a sculptor starts by making a model, often in clay, covering it with wax, and then adding a plaster shell with rods for reinforcement. The wax is melted away in a kiln, leaving a negative space into which molten metal is poured. After the metal cools and hardens, the mold is destroyed to reveal the unique sculpture, which is then polished and finished.