The following video and document highlights the steps we use to convert an EPUB eBook created with app.bookcreator.com into a print-ready PDF for on-demand color book printing with Lulu.com. In past years we have provided these instructions to students and taught them how to complete these steps. However, this process is a bit complicated and we've found with experience it's easier to have a teacher assist students with this final process.
So, our process today is to ask students to "turn in" their completed EPUB book via Google Classroom, and then a teacher converts that file to a Lulu.com print-ready PDF (following the steps below) and completes the analog / paper-based publishing process. The teacher then provides the unlisted Lulu.com book ordering link to the student, so they can order 1 or more copies of their book.
Here are some blog posts about the process of taking Book Creator eBooks and printing physical books with those files:
Facilitating Student eBook and Book Publishing with Book Creator and Lulu (Wes Fryer, January 2020)
Collaborating on a printed book for Book Week (Jose O'Donovan, November 2018
From Book Creator to printed book (Jane Ross, June 2015)