“Phantasmagoric Painting: Hans Richter, Theo van Doesburg, and László Moholy-Nagy between Canvas and Screen,” which is the first chapter of my second book, Art in the First Screen Age: László Moholy-Nagy and the Cinefication of the Arts, revolves around competing operative ontologies of the screen. More precisely, it distinguishes the “canvas” (Leinwand) and “film-canvas” (Filmleinwand) central to essentialist definitions of art and film (Greenberg, Arnheim, et al.) from the unheralded “screen” (Schirm) promulgated by avant-garde artists and theorists like Moholy-Nagy, Richter, and van Doesburg. In the essentialist readings of interwar art, the canvas/screen foregrounded its own properties (flatness, rectangularity, etc.) in a self-critical effort to delimit “the unique and proper area of competence” of each medium (Greenberg). An alternative effort, however, endeavored to construct a screen that would facilitate the (Hegelian) collapse of image and viewer, art and life. This avant-garde screen, as I demonstrate through meticulous historical analysis, had all the properties of the phantasmagoric screen, even if contemporaneous critics and recent scholars failed to make the connection. In the case of interwar abstract painting and film, the distinction between the modernist dream of self-reflexivity and the avant-gardist dream to merge art and life hinged on the infrathin difference between canvas and screen, the assertion of limits and the dissolution of boundaries. This reading is only possible through a synthesis of media archaeology and rigorous art history.