Blue period, blue traces, blue sponges... Yves Klein deserved his nickname of "Yves the monochrome". Even though he used many other colours, it is the colour of the sky that he chose above all, used over and over again and that he made into not just a mode of expression but a sort of spiritual energy. Klein had the idea of using directly the naked bodies of his models as "living paintbrushes", inventing by his strange sessions, between ritual and striptease, a whole catalogue of new forms. At the same time, intuitively, almost naively, he went through both the history of legendary pictures, the history of the peculiarities of nature and the noble history of nudes in painting. The Anthropométries are both a meditation on imprint, trace, disappearance and coloured variations on the theme of incarnation.