Jackson Pollock was the leading figure of Abstract Expressionism and the inventor of 'drip painting.' He abandoned the traditional easel, instead tacking large canvases to the floor and moving around them, dripping, pouring, and splashing household enamel paint using sticks and hardened brushes. This physical, rhythmic process led critic Harold Rosenberg to coin the term 'Action Painting.' Pollock believed that the canvas was not a space for an image, but an arena in which to act. His works, such as 'Autumn Rhythm (Number 30),' have no central focal point; the eye is meant to wander across the tangled web of lines. While critics initially mocked him as 'Jack the Dripper,' his work was a radical departure that shifted the center of the art world from Paris to New York City after World War II.