Bridget Riley has explored visual perception using geometric patterns since the 1960s, when her paintings were central to the Op Art movement. In printmaking, she was particularly drawn to the medium of screenprint, finding ways to layer form, line, and color to investigate the optical effects of color relationships and juxtapositions. Indeed, Riley was influenced by the color theory of the Neo-Impressionists, including Georges Seurat and Paul Signac. In Elapse, luminous lines of blue, pink, and green undulate against a gray ground, creating a dynamic and pulsating surface on flat paper.