n 1937, Antonio Bonet, Juan Kurchan and Jorge Ferrari-Hardoy apprenticed under architect/designer Le Corbusier in Paris; the following year they invented the "BKF" or butterfly chair. In 1941, MoMA design director Edgar Kaufmann Jr. brought the first two chairs to the United States. One chair went to the museum, the other to Fallingwater, his home designed by Frank Lloyd Wright. Most people associate this retro cool looking chair with the 50's when it was being mass produced, its hard to believe it was actually designed in the 30's and first used in North America in a Frank Lloyd Wright house.
The chair was originally mass-produced by Artek-Pascoe. In 1947 Knoll acquired US production rights of the Hardoy butterfly chair, bringing international notice and commercial success to the design. Unlicensed knock-offs and the loss of a Knoll copyright suit have made this one of the most copied chairs of modern design and it became one of the most widely copied chairs in existence. After losing their claim of copyright infringement, Knoll dropped the chair from its line in 1951.
In 1997 these are resumed mass-production of the chair to the exact dimensions of the Knoll version. Their frames are solid steel and do not fold or disassemble. Both black and stainless steel frames are historically correct, while stainless steel offers additional benefits: stacks for easy storage; contains 75% recycled steel and is totally recyclable; does not corrode or rust as easily as ordinary steel. An estimated 5 million of these chairs were produced during the 1950's by numerous manufacturers under various name and all varying in size. Circa50 makes covers for any size. Today, the canvas covers in use at Fallingwater are made by Circa50.