Degas introduced Cassatt to pastel and engraving, while for her part Cassatt was instrumental in helping Degas sell his paintings and promoting his reputation in America. Cassatt and Degas worked most closely together in the fall and winter of 1879–80 when Cassatt was mastering her printmaking technique. Degas owned a small printing press, and by day she worked at his studio using his tools and press. However, in April 1880, Degas abruptly withdrew from the prints journal they had been collaborating on, and without his support the project folded. Although they continued to visit each other until Degas' death in 1917, she never again worked with him as closely as she had over the prints journal.