2.25" with his facsimile signature and text "People For Play East 85th St. Playground Ass'n., Inc." Sendak related to Ted Hake upon seeing one of these buttons that he made his first button while in high school making this his first for commercial purposes. Design is based on 2 boys in the book "Let's Be Enemies," 1961, written by Janice Udry and illustrated by Sendak. Only the third we've seen. Rare. Exc. and displays Mint. Our last example exceeded $300.00. See the next six items from the Sendak Collection.