Arne Jacobsen's famous Ant chair of 1952 was the starting point for a number of variants whose common element was a continuous plywood seat and back. This chair is the only version with timber legs: the other variants all have steel legs. The back is a more angular and blocky version of the most popular chair in the series, the sinuous 3107 chair designed two years earlier (see Circ.371-1970). This version is also sometimes known as the Grand Prix chair because it won the prestigious Grand Prix award at the Milan Triennale in 1957, the year of its introduction. Later it was made with steel legs, and renumbered 3130. A version was used by Jacobsen to furnish the National Bank of Denmark in Copenhagen, which he designed between 1965 and 1971.