In the late 1970s, during Schulz's negotiations with United Feature Syndicate over a new contract, syndicate president William C. Payette hired superhero comic artist Al Plastino to draw a backlog of "Peanuts" strips to hold in reserve in case Schulz left the strip. When Schulz and the syndicate reached a successful agreement, United Media stored these unpublished strips, the existence of which eventually became public. Plastino himself also claimed to have ghostwritten for Schulz while Schulz underwent heart surgery in 1983.