Hans Hinterreiter (Winterthur, Switzerland, 1902 - Ibiza, 1989) “A theory of form and color” This is copy 117 of 500. Hand-signed on the title page by Hinterreiter. Published by Carl van der Voort. Spain, 1967. 31 x 25 cm. Copy 189 of 500, signed, is currently held at the Helga de Alvear Museum of Contemporary Art in Cáceres.