Jennifer L. Roberts, Elizabeth Cary Agassiz Professor of the Humanities, Harvard University. In this six-part lecture series titled Contact: Art and the Pull of Print, Roberts focuses on printmaking as an art of physical contact, involving transfer under pressure between surfaces—a direct touch that can evoke multiple forms of intimacy. And yet it is simultaneously an art of estrangement: it requires the deferral, displacement, and distribution of artistic agency, and it trades in reversal and inversion. In this fifth lecture, “Interference,” premiered on the National Gallery’s website on May 23, 2021, Roberts explores how the layering of images in printmaking, especially when grids and regular linework are involved, often results in the emergence of interference or moiré patterns. While printers usually work hard to keep these disruptive eruptions at bay, some artists have cultivated them, allowing unruly patterns to emerge from the combination of seemingly rational image layers. Moiré patterns also bring printmaking into conversation with the sound arts, which are built on the same waves, frequencies, and beats that are used to describe print interference.