Untitled belongs tp the Blackboard series which Twombly began in 1966 with Night Watch and continued until 1971. Considered his most cerebral and most lyrical works, the blackboards are Twombly's finest examples of free-form writing with paint.
The circularity and loopy aimlessness of scrawls in Untitled activate the surface with gestures reminiscent of Jackson Pollock's "all-over" drip pictures, while the reductive quotient of line against monochrome background underscores the work's affinity with Minimalism. Twombly accomplishes all these references through a series of conversions that gives his pictorial expression an unmistakeable personal tone. His net of graphic zigzags, made with wax crayon which is rubbed off in some areas by hand, is instantly recognizable; as Roberta Smith noted, "It is more like handwriting than a typical painting touch" (R. Smith, "The Great Mediator" in H. Szeeman, ed., Cy Twombly, Munich, 1987, p. 16). The repetitive, run-on markings are ruminations in penmanship. Twombly could as well be dreaming of literary figures whose names often appear in drawings from the 1960s onwards: Homer, Virgil, Ovid, Montaigne, Valry, Mallarm. Indeed, much of Twombly's work suggests an unbroken continuity between verbal and visual experience. In the present work, the artist has retraced the rows of cursive loops several times, and each time the gesture is more erratic than the last. Here, the "script" coils and throbs through the pictorial space, denying any promise of final release. The ensuing effect is that of written language stripped of any legible content. By isolating a single gesture that he reiterates with variations in pace and tension, Twombly develops a systemic language which is akin to the experimental concrete music of the period.
Although seemingly abstract--like a scribble or a sound--the blackboards are in effect rooted in scientific reality. They are based on studies that chart the movement of air waves and water currents, in particular, Leonardo da Vinci's group of sketches for the Deluge, and his treatises on nature. This may explain why in 1968 Twombly produced a collage in which he juxtaposed an image of the Deluge from a facsimile of Leonardo's notebook with his own variations on it. In this light the cursive, energetic torrent of lines in Untitled represents a poetical vision of cosmic expanse, executed in response to the imagery and obsessiveness of Leonardo's scientific idiom.