On July 11 in London, Sotheby's will sell Dame Barbara Hepworth's Curved Forms (Pavan) sculpture as part of its Modern & Post-War British Art auction.
The sculpture, executed in 1956, is valued at £180,000-250,000 ($274,392-$381,100), and is expected to provide one of the top lots of the sale.
It is the second of two versions, with the other held in the Wakefield Permanent Art Collection.
Hepworth was predominantly a carver, and shied away from modelling. As a result, she was hesistant about the use of traditional bronze techniques.
This changed when the artist developed a technique to create the armature of a bronze before covering it with plaster, which she described as "like covering the bones with skin and muscle".
Curved Forms (Pavan) is an early example of this use of plaster, and is therefore an important work in the development of Hepworth's career.
At Christie's on July 10, a 1961 bronze sculpture by Hepworth will sell at Christie's with an estimate of £1m-1.5m ($1.6m-2.3m).
Also starring at Sotheby's is the largest work ever seen at auction by Ben Nicholson, who stood at the forefront of the British avant-garde with the likes of Hepworth and Henry Moore.
See our selection of art collectibles for sale.