“Paul Klee was of seminal importance to me,” the renowned artist Bridget Riley has said, “because he showed me what abstraction meant.” Falling ill with a degenerative disease in his later years, Klee’s work became highly geometrical—simple designs executed with heavy lines. Similarly, in Riley’s work of the 1980s and 90s, she began to cross stripes with diagonal shapes, a strategy designed to move the eye around the canvas. These studies are referred to as her ‘rhomboid’ paintings. The gallery has reopened by appointment, and Riley’s rhomboids are on display in conjunction with works by the Bauhaus master Klee, who is exhibited on the ground and first floors. —E.C.