For Yves Klein the colour blue was the ultimate expression of spiritual values, an image of the ineffable. "I have found it" he proclaimed to friends in 1949 during a brief apprenticeship in a London frame shop "a means of painting that was against painting, against all the anxieties of life, against everything. It was creation, and creation was health". To Klein's way of thinking, the admixture of ultramarine pigment and synthetic resin - the formula for the patented IKB or International Klein Blue - was not simply a plastic representation of the divine but an actual physical signifier of it. This revelation would instruct the rest of Klein's short but meteoric career. Although at first he experimented with a variety of powerful colours, in 1956 he began what he himself called his "Blue Period". Despite their apparent similarity, every monochrome was unique. "Each blue world of each painting, although the same blue and treated in the same way, presented a completely different essence and atmosphere," claimed Klein.
In contrast to the Abstract Expressionists, who were working concurrently but across the Atlantic, Klein sought to eradicate any biographical or narrative trace. All marks of self-expression were for him a distraction from painting's serious intent. Sensibility - the world of the soul - was more properly the domain of art, and colour was the immaterial medium of communication with this other world. The boundless blue of each monochrome was intended to provide an experience rich in openness and spiritual value. Klein hoped to stimulate a kind of aesthetic encounter which transcends the visible aspects of pictorial presence, bringing the viewer directly in contact with a heightened consciousness of life.