The line between fashion and art can be very blurred. This is true in the case of Yves Saint Laurent, prince of couturiers and tireless inventor of shapes, starting with the famous Trapéze line which he designed for Christian Dior when he was just twenty-two. With simplicity and freshness, his clothes would later evoke the atmospheres of the avant-garde, abstraction, concrete art. A colourist, Saint Laurent imagines pure and exuberant compositions, born from the assembly of flat surfaces in brilliant shades. Illusionist, he opposes black to white to create dynamism with skilful optical games. In the Parisian museum dedicated to him, today the designer's creations dialogue with the works of the German artist Claudia Wieser in a vibrant environmental installation. A conversation made of lines, colors, geometries, which winks at the aerial modernism of Vassily Kandinsky and Paul Klee, letting the absolute contemporaneity of Saint Laurent emerge with natural clarity.