Is there more “value” ascribed to works made by one foundry than by another? 

In terms of monetary “value” and interest to a collector or institution, there is often a higher value put on works produced during Rodin’s lifetime. All authorized casts made by any foundry are considered “originals.” However, casts that were made before Rodin’s death in 1917 are often appraised for higher amounts and fetch larger sums at auction. 

Many people prefer these lifetime casts because they find more beauty in the older patinas they bear.  Often these lifetime casts have interesting provenances (histories of ownership).  However, a cast made during the artist’s life would not have received more of Rodin’s attention than would a posthumus cast; his assistants took care of the casting process for him.  As the artist, he cared only about the modeling of the piece, not the casting, which was a matter for craftsmen, not artists.

Which is considered the “original” work, the bronze or the clay model? 

In painting, there is typically one work and therefore one “original.” In sculpture and other mediums such as photography and printmaking there are often multiple examples or “originals” of the same work. In Rodin’s work, all bronze casts authorized by the artist or by his heir, the French Nation, are “original.” The initial plaster or clay model can be thought of as a stage in a process; the result being the final finished bronze cast. All are equally important. 

Since about 1940, some have argued that works are original only if they are cast under the strict supervision of the artist. However, in Rodin’s day and in his studio, this standard did not apply; like most sculptors who preceeded him, Rodin himself did not supervise the casting of his works and reportedly did not even step foot in the foundries he patronized. 

How much polishing or finishing is done by the foundry? 

Typically, after a bronze sculpture is cast it is hand-finished to remove any imperfections left by the casting process. This procedure is called “chasing.” After the chasing has been completed, hot or cold oxides are applied to the surface of the bronze; these create a thin layer of corrosion. Depending on which oxides are used by the foundry, this thin layer can have a brown, black, green, blue, or red color. This colored layer is called the “patina.”  Rodin employed a painter who specialized in patinas and who directed the work of the foundries at this stage of their work.

What are the protrusions that appear on some of the bronzes – such as the bump on the lower back of the top figure in Ovid’s Metamorphoses or the lines on works such as Monumental Torso of the Walking Man? 

When using the lost wax method, there are conduits or pipes, called “sprues” and “gates” attached to the core model. These conduits are channels through which the heated wax escapes from the mold. The sprues and gates are removed during the chasing process. There are often also raised marks left by leaking bronze. Most artists of Rodin’s day would have these “flaws” removed and have the surface of the bronze chased to perfection. Rodin however often preferred to leave evidence of the casting process, to reveal what he believed to be a more dynamic surface.