How did the aesthetics of popular illustrated periodicals shape late-Victorian reader engagement? How did these terms of engagement relate to the role magazines played in emerging mass culture? My dissertation investigates these questions using evidence from four popular periodicals between 1885 and 1918: the Graphic, the Illustrated London News, Pearson’s Magazine, and the Strand. Readers possessed a print media literacy through which they could interpret the material traces of production that were part of a periodical’s aesthetics and situate a print object in its real and imagined socio-technological contexts, a capacity I describe as the technological imagination. Print media literacy also enabled readers to attend to how a physical print object mediated culture, which I describe as medial awareness.