n 1969, U.S. artist and educator Thelma R. Newman observed that plastics have caused “a silent revolution.” Art history and criticism have yet to grapple with the relationship between the plastic arts and plastic, that most prosaic of materials. Upon first glance, it may seem that art and plastic have little in common. Yet, plastic and art are imbricated in terms of value because both are context-dependent: art and plastic are containers for social meanings and cultural values. Plastic is a challenging material to think about because its many iterations can assume varying degrees of shape, texture, hardness, density, or color, and because the term “plastic” is used to denote the quality of being shaped or molded—an attribute that was once regarded as specific to aesthetics, but is now a commercial and manufacturing process. In this dissertation, case studies of art objects, criticism, and conservation from the1960s and the 1970s reveal that the concept of “plastic” was especially contested and malleable at this time. Drawing on cultural anthropology, continental philosophy, transgender studies, and polymer chemistry, this study parses out the relationship between plastic and plasticity as a dialectic of becoming plastic, or hardening into a stable form or category, and the movement of plasticity, a dynamic that destabilizes hierarchies. Art objects featuring synthetics exist on the same continuum as discarded consumer plastic, and these materials open the artwork onto the world in unprecedented ways, underscoring the work’s participation within greater networks of economy and ecology. The relationship between viewers and artworks is no longer purely aesthetic, or even broadly “spiritual” or “psychological.” These relationships are forged at the molecular level and demand new approaches to conservation and care.