Every possible buyer of an immaterial pictorial sensitivity zone must realize that the fact that he accepts a receipt for the price which he has payed 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 him, he must solemnly burn his receipt, after his first and last name, his address and the date of the purchase have been written on the stub of the receipt book.

p. 207 - 'Ritual for the Relinquishment of the immaterial Pictorial Sensitivity Zones', Yves Klein, 1957-59