Omstak chair by Rodney Kinsman for Bieffeplast (1971)Omstak chair by Rodney Kinsman for Bieffeplast (1971) This iconic Omstak chair was designed in 1971 by Rodney Kinsman for Italian Bieffeplast. With its industrial design and perforated steel seat, this chair is a timeless example of functional design from the 1970s. Style and functionality The Omstak is a perfect marriage between brutalist simplicity and ergonomic form. The perforations in seat and backrest provide ventilation and visual lightness,