Pratt Institute graduate Lewis Butler was one of the first designers who came to Knoll specifically to work in the Planning Unit — Florence Knoll’s revolutionary design consultancy devoted to office interiors. In 1950 he became a senior designer and assistant to Florence Knoll. He later recalled that “[Florence] would do the rough outline, and I would develop it and refine it further. I became an extension.” When Florence Knoll left the company in 1965, Butler was appointed as the head of the Planning Unit.
As was the case with the work of many Planning Unit members, Butler’s furniture designs were often intended to fill in the space between what Florence called the ‘star pieces’ of Bertoia and Saarinen. His simple designs were appropriately subtle and thoroughly modern. Ever-interested in visual and structural simplicity, an identifying mark of Butler's work is the wooden joint he often employed to avoid the use of excess hardware.