Esphyr Slobodkina (1908?2002), internationally renowned artist and author of the children's classic Caps for Sale, was among the first female American artists to explore abstraction and the first to use collage in American storybooks. She studied art in Russia and China before immigrating to the United States in 1928. She was a founding member of the American Abstract Artists group, and her work is represented in prominent museum collections across the country.

In addition to Caps for Sale Slobodkina also wrote and/or illustrated over 24 children's books. Over the decades she also completed hundreds of paintings and assemblage works that can be found in major museums in the United States.

Before her death in late 2002 Slobodkina left copious notes and illustrations for additional stories. Slobodkina encouraged her assistant and protégé Ann Marie Mulhearn Sayer to carry on her storybook work after Slobodkina's death. Many of Slobodkina's story ideas and characters (including Slobodkina herself) are incorporated into the continuing Caps for Sale book series.