Otto Piene, Der Himmel ist Gelb, 1981, Fire gouache on board, 68 x 96 cm | 26.77 x 37.8 in, # PIEN0003 Otto Piene, For Greco, 2001, Oil, traces of fire and soot on canvas, 102 x 122 cm | 40.16 x 48.03 in, PIEN0006 Otto Piene, Fleurs du mal, 1969, Sailcloth, ventilator, Dimensions variable, PIEN0007