Alloway confirmed his position as the pre-eminent British critic of avant-garde art and new American painting in a series of six articles titled “Background to Action” that appeared on the front pages of the fortnightly Art News and Review between October 1957 and January 1958. Four focused on recent American painting. The first article dealt directly with some of the artists in Modern Art in the United States—de Kooning, Rothko, and Clyfford Still, for example—enabling Alloway to demonstrate his intimacy with artists’ and critics’ statements and writings. Greenberg's phrase about “expendable conventions” is quoted and, although Rosenberg is not, his influence is clearly apparent in Alloway's premise that, for these artists, “Paint is used existentially.” Alloway explained that the Existentialism he had in mind “is neither pessimistic, in a 1940-ish way, nor paradoxical, to provide bitter entertainment for worldly readers. The Existentialism I have in mind is that obvious part of the philosophy which dramatises present action with a startling rigour and intensity, stripped of precedent and custom, oriented towards a problematic future. Painting like this means Pollock, or like Rothko.” Criticism like this also meant Rosenberg.

In the second article Alloway develops the question of meaning, arguably another of the Existential aspects. “Meanings in art,” he points out, “have a tradition of clarity with only peripheral ambiguities. There is, however, in Action Painting, an emphasis on the extensive or multiple meanings of the work of art.” This was not a collapse into subjectivism: “I do not mean by this that anything goes. However, instead of there being one correct and various incorrect readings of a work of art there may be more than one reading that should not be called incorrect.” This related to Existentialism in two ways: first, the spectator now had a burden of responsibility for interpretation of the multi-evocative imagery; and second, the artist no longer resolved an artwork to the point of closure, thus now ensuring that “The spectator completes the configuration of the artist's gesture.” The active spectator claims her or his part of the action (painting). In his 1952 essay, Rosenberg had not commented on the role of the spectator, other than remarking, in passing, that, as the painter was now an actor, the spectator had to “become a connoisseur of the gradations between the automatic, the spontaneous, the evoked.”