12 rubber stamps, 2 ink pads black and red ink. Instructions by Karl Gerstner and dieter rot on doublesheet. 28 x 28 x 7 cm in box made by workshop Galerie Der Spiegel, Cologne. Published by Tam Thek editors K. Gerstner and D. Spoerri Dusseldorf. Number 23/111 and signed. (announced 1965 catalogue 'edition mat mat'). DR. CW. 20 n. 34.. . [ 1207].