‘The technique was revolutionary’: Ha Chong-Hyun, the 91-year-old South Korean artist who turned painting inside out

In his trailblazing work, paint is pushed through the back of hemp to create spare, striking paintings. Abstraction is a form of rebellion, he says – and he has no intention of slowing down In the early 1970s, the Korean artist Ha Chong-Hyun had a simple but novel idea: why not apply oil paint to the back of a surface rather than the front? Instead of canvas, he stretched pieces of hemp, a coarse…