The German artist Gerhard Richter has always had two approaches to painting. The first is photorealist, in which his signature blurred portraits stare out of the canvas. The second is abstraction, which sees Richter dragging a squeegee along wet paint, layer after layer. He began experimenting with abstraction early on, in the late 1950s, with ink on paper. He has overpainted photographs, and worked with pencil and charcoal. This exhibition features 60 Richter experiments made between 1999 and 2021. —E.C