Henry Moore valuation

Bronzes are editioned, generally in numbers of seven or nine plus artist's copies, and cast number, foundry, patina and whether a cast was made in the artist's lifetime are the substance of a valuation; the Foundation holds the archive and unauthorised casts are a known problem. The carvings in wood and stone are unique and sit far above the bronzes. Maquettes are numerous. Drawings and the Shelter Drawings are a significant separate market, and Moore's lithographs and etchings from the 1970s onwards are plentiful and modestly valued.

The Henry Moore Foundation at Perry Green runs a research and review service for works whose attribution is uncertain. It works in two stages. The Foundation's researchers first check the work against the catalogue raisonné of sculpture, drawings and graphics, their own unpublished records and a database of recorded fakes and misattributions; only where the evidence warrants it does the work go before an expert panel in person. A bronze or drawing that has never been catalogued needs this before a sale.

The lithographs and etchings are the opposite case: plentiful, recorded and usually straightforward. What matters is whether a sheet is signed and numbered in pencil or comes from an unsigned book or portfolio edition, its condition, and whether it is an original print at all, since posters and reproductions after the sculpture are common. A small bronze with a plausible story and no catalogue number is where the care should go.

The Leeds School of Art set up a sculpture studio especially for Moore when he arrived in 1919, and there he could see the modern pictures collected by Sir Michael Sadler, the university's vice-chancellor. At the Royal College he was set to copy a marble relief with a pointing machine; he carved it directly instead and faked the machine's prick marks. A travelling scholarship in 1924 took him to Italy for Giotto, Giovanni Pisano and Michelangelo, and in Paris he saw a plaster cast of the Toltec-Maya Chac Mool, the figure behind his reclining women.

His first visit to America came in 1946, for a retrospective at the Museum of Modern Art. Family Group, made in 1950 for a school in Stevenage, was his first large public bronze, and in 1958 he carved a marble reclining figure for the UNESCO building in Paris. From the late 1940s he worked out his forms in clay or plaster and had them cast by the lost-wax process, with assistants at Much Hadham who included Anthony Caro and Richard Wentworth. The Foundation, set up in 1977, keeps his house and seventy acres of sculpture grounds at Perry Green open to visitors.