The posthumous cast was made from the original plaster or the original clay, that Giacometti made himself but most respected collectors believe that one should attempt to get a cast that was made during the lifetime of the artist and not look at a piece of sculpture made posthumously.
Giacometti authorized Peggy Guggenheim to cast an edition of six bronzes from her plaster «Woman Walking» of 1932 and to sell them as she was concerned that the fragile plaster would disintegrate in the Venetian climate where she had her collection. Three years after Giacometti's death in 1966 she had an additional, unauthorized cast made from the original plaster. None of the casts carried foundry marks and several were unnumbered. The problem is that "surmoulages" (overcasts) were made from one of the bronzes without Peggy Guggenheim's knowledge and appeared in the U.S and Europe. Up to 100 illegal surmoulages made from finished bronzes were produced.
Regarding Rodin, some 700 subjects have been cast in bronze since his death and several experts have questioned the Musée Rodin's practice of casting the artist's plaster models of anatomical fragments, something which is much questionable.
Now, the only way to tell the difference between lifetime casts and posthumous ones created by the Alexis Rudier foundry in Paris, the artist's exclusive founder between 1902 and 1952, seems to be through the provenance. Still, lifetime casts should be considered as more valuable than posthumous ones.
Japanese Ryoei Saito paid $ 4,29 million at Sotheby's in New York for bronze casts of «The Burghers of Calais» made by the Rodin Museum in the 1980s
He later donated them to the newly formed Rodin wing at the Shizuoka Prefecture Museum outside Tokyo.
It has been estimated that at least 6,500 bronzes and possibly many more of 30 different subjects were cast by the Rodin Museum bringing it an income of between $ 2,5 million and 4 million a year.
B. Gerald Cantor, founder and chairman of Cantor Fitzgerald, a financial holding company, and his wife, Iris, president of the Iris and B. Gerald Cantor Foundation, were one of the main customers of the Museum. They acquired 750 works and placed about 435 of these in 70 institutions around the world.