Originally Posted by jacktanner
Yes, that's exactly right.
I'm happy to test the portfolio theory and report back. How can I tell if my PDF is a portfolio, and how can I convert the portfolio to a flat PDF? I'm on Windows and Linux. Alternatively, I can send the possibly-portfolio PDF to whoever wants to investigate it.
If I were you I would investigate other tools to add the metadata to the pdf prior to adding them to calibre. I'm not a pdf fan when it comes to ebooks but I have seen other tools for pdf metadata editing mentioned in some of the threads. Google might shed some light