Cor Unum (Den Bosch 1953 – ). Cor Unum is a ceramic workshop in ‘s-Hertogenbosch, which started in 1953 as a social workshop where utility ceramics were developed and produced. Led by the designer Zweitse Landsheer (1928 – 2010) in the 1970s. Other designers included Geert Lap, Ettore Sotsass, Jan Schuurkes and R.W.J. Veersema. In the mid-1990s, the Cor Unum management consciously opted for the niche of exclusive design.