Conversation so far:
What is an example of Robert Crumb's early work?
His first job, in 1962, was drawing novelty greeting cards for American Greetings in Cleveland, Ohio.
How long did Robert Crumb work at American Greetings?
He stayed with the company for four years.
Did Robert Crumb like his job at American Greetings?
Dissatisfied with greeting card work, he tried to sell cartoons to comic book companies, who showed little interest in his work.

Question: What job did he do after he left American Greetings?
Self-contained rewrite: What job did Robert Crumb do after he left American Greetings?