Fast-forward to a little-known exchange between photographer/ filmmaker Hollis Frampton and sculptor Carl Andre in 1962. (3) Frampton suggests that Andre's typewriter poems are not concrete enough because they mingle sound and sight just as Rimbaud's poem "Voyelles" (1870–71) had done by assigning each vowel a color: "What must be brought about is the divorce of this whole precinct of our activity from the vague shapes of synaesthesia." Considering that Andre's poems were hardly mushy (the one in question is "roseroseroseroserose"), we can see just how far Greenberg's hardheaded approach had taken artists by the 1960s—indeed beyond Greenberg, who had by then retreated into his own kind of sensory haze called "opticality." (4)