Why was lost-wax casting used to make fully rounded metal reliefs?

The lost-wax process is a traditional method of metal casting that allows for the creation of complex, refined forms, including fully rounded metal reliefs and statues.12

The primary reason this technique is used for such works is its ability to produce hollow castings, which are essential for larger sculptures. By incorporating a heat-proof core within the mold, the process ensures that molten metal only fills the narrow cavity between the core and the outer investment, rather than creating a solid, heavy, and potentially unstable mass.12

To achieve this, the sculptor creates a wax model over a refractory core. Metal pins are hammered through the wax into the core to secure it in place before the entire assembly is covered in a heat-resistant mold. When the wax is melted and drained away, it leaves a precise space that, once filled with molten metal, results in a hollow, lightweight, and detailed reproduction of the original design. This method is particularly valued for its capacity to capture intricate surface details and complex shapes that would be difficult or impossible to achieve through simpler hammering or solid-casting techniques.123