Major artist of the mid-20th century with a dazzling career, Yves Klein's artistic work consists of revealing the trace of the living, making the invisible visible, manifesting sensitivity in its purest form. His interest in the immaterial pushes him towards singular experiments where mystical reflections, performances and technologies are mixed. Known worldwide thanks to his almost exclusive use of ultramarine blue, the artist considers color to be the most appropriate medium for revealing invisible space and its depth. Color becomes matter: it inhabits space while the line only furrows it.