I am often asked by customers interested in a sculpture: What is an artist's proof? As a painter, I know that in making prints, an artist will often pull proofs to see how the print quality is progressing. Once it hits that quality, the edition is printed.
In sculptures however, I was a bit confused, so I decided to contact one of the sculptors on Sporting Artisans - Ronnie Wells - and a foundry - Northwest Casting - in Bozeman, MT to try to get a clearer idea.
In sculptures, it is not uncommon for the artists to set aside a number of proofs that are set apart from the regular limited edition. Northwest Casting says that an artist can set aside three - or even more for that matter. But they are separate from the regular edition. The regular edition is often cast by the foundry as an order comes in because it is so cost prohibitive for the artist and the foundry to produce all of the editions at once. This is why when you order a sculpture - it usually has to be cast for you and this can take 8 - 12 weeks - sometimes longer.
I talked with Ronnie Wells wife Patricia who explained that an artists proof is given a more hands-on treatment from the artist. This includes making sure the patina is right, polishing it and making sure it lives up to the highest of standards. The proof is also a "limited edition" in that only a select number are produced - usually three. Each is usually signed with "AP 1" "AP 2" etc.
Artist's proofs do not adversely affect the value of the limited editions, but because they are a small number and set aside by the artist themselves, they tend to be higher in value than the redular edition. They may have very slight variance from the rest of the edition that is cast, but that simply depends upon the sculptor. The "stamp" the sculptor puts on the artist's proofs simply adds more to the value.