"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."

“detailed biography of Yves Klein”

“This period of blue monochrome was the product of my pursuit of the indefinable in painting which that master, Eugène Delacroix was able to indicate even in his day.”

“It was in 1947 that the idea of a conscious monochrome vision came to me.. .Pure, existential space was regularly winking at me, each time in a more impressive manner, and this sensation of total freedom attracted me so powerfully that I painted some monochrome surfaces just to 'see', to 'see' with my own eyes what existential sensibility granted me; absolute freedom! But each time I could neither imagine or think of the possibility of considering this as a painting, a picture, until the day when I said: Why not?”

“In 1946, when I was still an adolescent, I went and signed my name on the other side of the sky during a fantastic 'realistico-imaginary' voyage.”

“A bill for 20 grams of Pure Gold, for one painted area of sensibilized immaterial.”

“Dubbed as a Knight of the Order of Saint Sebastian, I espoused the cause of pure colour, which has been invaded by guile, occupied and oppressed in cowardly fashion by line and its manifestation; drawing in Art. I aimed to defend and deliver it, and lead it to triumph and final glory.”