By default, each chapter in your book and the book itself will build two different PDF files for download: mobile and printable. Mobile PDFs are optimized for tablet viewing, while printable PDFs are optimized for printing on U.S. letter-sized paper.
To make sure that PDFs are enabled on your chapter, while editing your chapter, click on Formatting and ensure that the PDF Rendering option is enabled. A similar option is available when editing the book's main page.
Once PDFs are enabled for your book or chapter, the download link will appear in the dropdown menu. However, PDFs must be built by the server in the background and may not be instantly available. Chapter PDFs generally take several minutes to build (depending on server load), and book PDFs may take a few days. This process can be expedited by the administrator upon request if needed.
Additionally, building PDFs is a difficult, highly-technical task, and authors should be aware that the PDFs generated by the automated system might not look exactly like the web version. If there are major issues, please contact a site administrator to see if improvements to the PDF building algorithm can be made. Otherwise, if you need your PDF to look a particular way, you may also build the PDF yourself in another program, host it on another site (like Google Drive), and include the link as an alternative PDF download link.