At what point does an artist become so thoroughly absorbed into the mainstream art world that the term “outsider artist” no longer applies? And is it even a useful term in the first place, or does it only constrain our understanding of an artist’s work? These questions are at the heart of the current conversation around self-taught artist Thornton Dial, who was born into poverty in Alabama in 1928 but lived to see his work acquired by some of the most august museums in the world.