The lost-wax technique is that the commonest technique for creating bronze figures and sculptures. Though the precise process varies from foundry to foundry, the technique has been relatively standard since its first use in c. 3700 BCE. The artists begin with a model that they form a mold. We employ a soft material like silicone for the inner mold, which must be malleable enough to supply a particular negative of the first object. The outer mold is rigid, often made of plaster. Molten wax is then poured into the mold thinly coating its inner surfaces. After it's cooled the wax is faraway from the mold and ‘chased’–perfected to get rid of any flaws or evidence of casting–wax rods are added to form channels through which the molten bronze can flow and gas can escape. A rigid cast, again often plaster, is made round the wax mold and therefore the entire object is fired during a kiln. This both solidifies the plaster and melts the wax which drips out of the mold through the channels. This leaves a prefect negative of the artist’s object into which the liquid bronze is poured.
After it's cooled, the casting is faraway from its plaster mold, the bronze which formed in situ of the wax rods is removed, and therefore the surface is ‘chased’ once more, polished, and sealed. A well-cast bronze sculpture is weatherproof and very durable.