Thanks for the link and reply.
I had some trouble producing Prince PDF from an EPUB file without embedded font, until I realized that the PDF was using a different font than the one on my Linux, a font whose metrics were slightly larger, and of course, it spoilt everything... With your last EPUB, everything is fine.
To provide users with a consistent display on all kinds of supports, I think it should be a good practice to embed a font.
Again thanks for your help and demo.