When did Jackson Pollock begin pouring and dripping paint onto canvases?

Jackson Pollock first began using the process of pouring or dripping paint onto a flat canvas in 1947.1

By the late 1940s, he had fully developed this "drip and splash" method, which involved abandoning the traditional paintbrush and easel. Instead, he laid his canvases on the floor and used various implements—such as sticks and knives—to manipulate enamel or aluminum paint, creating complex linear patterns that recorded his physical gestures. This technique, which became a hallmark of Abstract Expressionism and action painting, allowed him to build up layers of color and texture, as seen in early works from this period like Full Fathom Five (1947) and Lucifer (1947).213