“Every possible buyer of an immaterial zone of pictorial sensibility must realize that the fact that he accepts a receipt for the price which he has paid takes away all authentic immaterial value from the work, although it is in his possession. In order that the fundamental immaterial value of the zone belong to him and become a part of his life, he must solemnly burn his receipt.” “Ritual for the Relinquishment of the Immaterial Pictorial Sensitivity Zones,” Yves Klein and Dino Buzzati, 26 January, 1962, Paris. 280px-ZoneImmaterielKlein2.jpg en.wikipedia.org. Text: Klein Archive, via Thomas McEvilley, Yves Klein: Conquistador of the Void, p. 56. Yves Klein Retrospective 1928-1962, Institute for the Arts, Rice University, Houston, 1982.