Illustrator Ralph Voltz is a key visual voice behind many titles in Penguin Random House’s popular Who Is / Who Was / What Is series, bringing modern energy and clarity to nonfiction for young readers. His cover artwork, seen on books such as Who Is Timothée Chalamet?, Who Was Cleopatra?, What Is the Grand Ole Opry?, Who Is Jenna Ortega?, and Who Are Taylor Swift and Travis Kelce? blends bold color, expressive portraiture, and carefully researched likenesses to make real people and cultural icons feel available and accessible. Voltz’s illustrations strike a balance between realism and stylization, helping each subject feel iconic, and his covers play a major role in signaling the series’ modern, engaging tone on shelves worldwide.