When using Calibre's E-book Viewer, there is a button to "print to PDF":
Clicking it shows some options for "print to PDF":
I can successfully convert various ebook files to PDF this way. However this conversion process only converts files one at a time.
How can I mass "print to PDF" multiple files?
• Using Calibre Library, I can mass convert multiple books to PDF by selecting the books and clicking the "Convert books" button:
Clicking on the button opens a window that shows many options:
No matter how I experiment with these settings though, there simply is no way for Calibre Library to achieve the output that looks like the one we get from Calibre E-book Viewer's "print to PDF" function. As such, I don't think it's possible to do it using the converter in the Calibre Library.