Bronze casting is the process of creating a sculpture in bronze by pouring molten metal into a prepared mould. The technique has been used for over five thousand years and remains the principal way contemporary sculptors produce work in metal. Bronze itself, an alloy primarily of copper and tin, is prized for its strength, its workability and the rich patina it develops over time.
Most contemporary bronze sculpture is produced using the lost-wax casting process, a technique virtually unchanged since antiquity.
The sculptor first creates an original in clay, wax or another workable material. A flexible mould is taken from this original, then used to produce a hollow wax replica, an exact copy of the intended sculpture, made in wax rather than bronze.
This wax replica is coated in a heat-resistant ceramic shell. When the shell is heated in a kiln, the wax melts and runs out, hence ‘lost wax’, leaving a precise hollow cavity. Molten bronze is poured into the cavity and allowed to cool. Once solid, the ceramic shell is broken away to reveal a rough bronze cast, which is then chased, polished and patinated by hand to produce the finished work.
Bronze sculptures are usually produced in small editions, typically three to twelve casts of a given work, plus a small number of artist’s proofs. Each cast is numbered in the form ‘3/9’ and stamped with the foundry mark and the artist’s signature. Although every cast comes from the same original, subtle differences in patina and finishing mean no two casts are quite identical.
Patina is the surface finish of a bronze, achieved by treating the metal with heat and chemical solutions to produce a controlled colour and texture. Patinas range from rich browns and blacks to greens, blues and reddish tones, and are integral to the sculptor’s intention. A bronze’s patina will continue to develop slowly over time, particularly outdoors.
Bronzes are remarkably durable and require minimal care. Indoor pieces benefit from occasional dusting and an annual light wax; outdoor bronzes are virtually indestructible and their patinas will weather naturally. When considering a bronze, look at the quality of the casting and chasing, the depth and consistency of the patina, and the documentation of the edition.
At Byard Art, our sculpture offering includes editioned bronze work from contemporary artists, with full provenance documentation for every cast.
