Yves Klein "L'Arbre, grande éponge bleue", 1962 (today's visit at Centre Pompidou)

It was in 1956 that Ives Klein made his first blue monochromes. Winner in 1957 of a competition organised by the town of Gelsenkirchen in the industrial Ruhr, Klein was commissioned to produce a group of "sponge reliefs" and monumental monochrome panels, inaugurated in 1959. It was between these two dates that the sponge, at first one of his tools as a painter, became one of his materials. This "tree" of sponge and plaster, which combines the processes of impregnation and of the direct impression of nature on the work, is Klein's most monumental sculpture and one of the last pieces he ever made.