Sometimes we need to go to the source...
“Native Files” is simply a term that represents the original files used to create your PDF.
Why do we sometimes ask for these files?
Unfortunately, not all “Print Ready PDFs” are created equal. The quality of the PDF greatly depends on a combination of which software was used and the settings that were configured when exporting/saving as a PDF. Some software (including all Microsoft products) do not gracefully retain all required information to successfully produce a high quality print. When this happens, we need to make manual corrections to the PDF to compensate; this is where issues can occur.
Working with the book’s native files is the only way to ensure that each book is printed with the highest quality that our client’s demand – and guaranties the greatest level of flexibility when performing alternations. The added benefit is that if an alteration is indeed needed, it can be done efficiently without needing for you to create another PDF.
If you had a designer help put together your book, they will have the native files.