The Bertoia side chair is a steel chair. The frame is a welded steel construction.The side chair frame is available in chrome, and black, bronze or white Rilsan finishing.The Knoll logo is stamped into the base of the chair.Harry Bertoia's delicately industrial Side Chair is among the most recognised achievements of mid-century modern design. Like Saarinen and Mies, Bertoia found sublime grace in an industrial material, elevating it beyond its normal utility into a work of art.