In the wake of midcentury Abstract Expressionism, its extravagant gestures and fierce abandon, a new movement took hold in the U.S. and the U.K. It played with the saturated, populist, middlebrow imagery that had come to define modern life—plastics, advertisements, television iconography. The “pop” in the term pop art was an abbreviation of “popular,” and it marked a swing away from the elitist principles of abstraction. Pop’s pioneers are now household names, and include the tongue-in-cheek Roy Lichtenstein, the crazy-haired Andy Warhol, and the enigmatic Panamarenko. At S.M.A.K., 40 recently acquired pop masterworks spotlight this postwar movement. —E.C.