Painter and critic Matthew Collings charts the rise of abstract art over the last 100 years, whilst trying to answer a set of basic questions that many people have about this often-baffling art form. How do we respond to abstract art when we see it? Is it supposed to be hard or easy? When abstract artists chuck paint about with abandon, what does it mean? Does abstract art stand for something or is it supposed to be understood as just itself? It turns out there are hidden rules to abstraction that viewers of this intriguing, groundbreaking programme may never have expected.