Final answer:
In lost-wax casting, the sculptor uses a clay mold coated in wax. Heat is applied, causing the wax to melt and flow out of the mold, leaving channels for the molten metal to be poured.
Step-by-step explanation:
In lost-wax casting, the sculptor begins by making a clay mold of the intended sculpture, coats it in wax, and applies an outer layer of plaster to it, fastening metal rods to hold the shell in place and wax rods to vent the mold. Intense heat is then applied, causing the wax to melt and flow out of the mold. This step leaves open channels into which molten metal is poured.