Bertoia Diamond Chair

The Diamond chair is a lattice of steel rod, welded into an open grid and bent into a broad, shallow shell whose outline, seen from the front, is a diamond with softened corners. The shell rests on a separate base of bent rod that meets the floor in two long runners. It is about 85 centimetres wide and stands 75 high. A loose pad can be laid on the seat, or a cover drawn over the whole shell; bare, the chair is almost transparent.

Harry Bertoia was an Italian-born metalworker and sculptor who had won a scholarship to Cranbrook in 1937, where he met Florence Schust, later Florence Knoll. He spent the mid-1940s in California working with Charles Eames on moulded plywood, and left in 1946, frustrated that his contributions went uncredited. In 1950 Hans and Florence Knoll invited him to Pennsylvania and gave him a workshop in an old garage at Bally, asking only that he show them anything interesting. He came back with a series of wire chairs, which Knoll introduced in 1952. Bertoia also designed the jigs on which they were made.

The chairs were made by hand at first, because no suitable means of mass production could be found. The original seat edge, two thin wires welded on either side of the mesh, ran into a patent held by Eames for Herman Miller's wire chair, and the edge was redrawn as a single thicker wire, the way the chairs are still made. Bertoia said they were mainly made of air, like sculpture. Knoll paid him well enough that he could give the rest of his life to sculpture.

Knoll says the Bertoia collection has been in continuous production since its introduction. The Diamond chair is still made to order with a seat pad or full cover, and in London Heal's sells it for £1,687.