Eight assistants, two weeks of drawing for ten hours a day. The result, an almost invisible artwork. Its creator Alan Johnston explains



Alan Johnston was commissioned to create a piece of art for the ceiling of Tate Britain’s new cafe. He and his assistants spent 2 weeks lying flat on their backs as they delineated a painstaking lattice of pencil mark. At first glance Tactile Geometry looks like a falling shadow. Only when you approach it closely is the secret revealed. Johnston talks to TateShots about his process and intention.