Tyler Green traces the development of the dominant vertical as a compositional device in the works by Barnett Newman and Clyfford Still.

Green writes: "Around 1927 or 1928 Still began painting trains moving through the flat, open West, possibly the high plains around Spokane, Wash., where he was living… Extending upward from these trains is a thin sliver of smoke. That wisp doesn’t go from the top of the painting to the bottom of the painting, but you can see Still playing with the idea, putting it away, and then coming back to it. By 1946 Still is including single, thin, top-to-bottom verticals in his paintings, such as PH-945… The first Newman painting to feature what we might now call a 'zip'," Green continues, "is 1946’s The Word I… Throughout 1946 Newman would develop that vertical, presenting it as non-tapering in 1946’s Moment… Newman kept playing with the vertical form until he isolated it in 1948’s Onement I."