Previously on X-Men: The Making of an Animated Series (Book)

Previously on X-Men: The Making of an Animated Series is a book by Eric Lewald, with help from his wife Julia, on the making of. The book was released in Fall 2017, on the series' twenty-fifth anniversary.

The book is story editor and writer Eric Lewald's personal, inside account of the making of the series. In addition, he interviewed thirty-six of the artists, writers, voice actors, and executives who helped make the series. It also contains production pictures, concept art, and storyboards. In addition, he included testimonials from fans.

Julia convinced Eric to write the book after pointing out how beloved and influential the series had become. They worried that with 20th Century Fox owning the X-Men and Fantastic Four and Marvel Entertainment/The Walt Disney Company owning most of the rest, that no one was celebrating the popular show and that it had no home. They compared X-Men to the child of an angry divorce, as Marvel had sold the rights during their bankruptcy problems. They felt that if anyone was going to celebrate the series they should be the ones as they worked on it. Preparing for the twenty-fifth anniversary gave them a deadline to work within.

Charlotte Fullerton provided the artwork for the book as she had kept the original digibeta of almost six hours of Fox Kids promotional materials. Due to rights issues, Marvel did not participate in the book nor would they allow screenshots from the series. The promotional materials are considered fair use.

When first announced, the title was X-Men: TAS - The Making of a Surprise Number One Hit. It was also called Previously on X-Men: TAS - The Making of an Animated Series.

Will Meugniot designed the cover