Warhol was an early adopter of the silk screen printmaking process as a technique for making paintings. A young Warhol was taught silk screen printmaking techniques by Max Arthur Cohn at his graphic arts business in Manhattan. While working in the shoe industry, Warhol developed his "blotted line" technique, applying ink to paper and then blotting the ink while still wet, which was akin to a printmaking process on the most rudimentary scale. His use of tracing paper and ink allowed him to repeat the basic image and also to create endless variations on the theme, a method that prefigures his 1960s silk-screen canvas. In his book "", Warhol writes: "When you do something exactly wrong, you always turn up something."