Klein famously declared the blue sky to be his first artwork and from there continued finding radical new ways to represent the infinite and immaterial in his works. One such strategy was monochrome abstraction—the use of one color over an entire canvas. Klein saw monochrome painting as an “open window to freedom, as the possibility of being immersed in the immeasurable existence of color.” Although he used a range of colors, his most iconic works often featured International Klein Blue, a shade of pure ultramarine that Klein claimed to have invented and trademarked. He used materials like water, fire, and air to construct his works and staged a “leap into the void” for a self-published newspaper. Blue Monochrome is one from a dizzying array of innovations that Klein pursued in order to cultivate a new aesthetic consciousness. Undivided by drawing and seemingly untouched by the artist’s hand, the radiant field frees color from the confines of form. That liberation extends to International Klein Blue, the medium Klein developed with a chemist: pure color powder in a lightweight, virtually invisible resin solution that grants the individual grains unprecedented autonomy, rather than pigment bound with oil, which had a dulling effect the artist dreaded. Applied evenly with a roller, the profound hue suggests a potentially infinite visual expansion—an impression further encouraged by Blue Monochrome’s generous dimensions and subtly softened corners, which Klein carefully rounded. Yet the minutely textured matte surface also exerts a powerful attraction in its own right. Klein proposed that art was evolving toward the immaterial, progressively leaving behind physical objects in favor of impalpable effects and feats of ideation, and he conceived his intensely ultramarine canvases as essential stations on this path. This exploration also included ephemeral performances with the paint-smeared models that he called “living paintbrushes” and the sale, via certificate, of otherwise intangible “zones of immaterial sensibility.” At the same time, Klein acknowledged the allure of sensual immediacy, noting, “The more one lives in the immaterial, the more one loves matter.” Monochrome abstraction—the use of one color over an entire canvas—has been a strategy adopted by many painters wishing to challenge expectations of what an image can and should represent. Klein likened monochrome painting to an "open window to freedom." He worked with a chemist to develop his own particular brand of blue. Made from pure color pigment and a binding medium, it is called International Klein Blue. Klein adopted this hue as a means of evoking the immateriality and boundlessness of his own particular utopian vision of the world. Credit: The Sidney and Harriet Janis Collection Object: 618.1967 Image © 2019 Artists Rights Society (ARS), New York / ADAGP, Paris Text © MoMA - Museum of Modern Art, New York