New to the forum here, but I've been creating Blurb photobook for quite a while using the various Scribus 1.4.x versions. Alas, since around summer 2015, my PDF/X-3s uploaded to Blurb are rejected.
Blurb support was helpful enough to fix this in two cases by re-processing through Adobe Distiller, but they certainly won't do it for all future uploads. According to them "While Scribus claims to be PDF/X-3 2002 compliant we have seen that they re-encode fonts which isn't actual true compliance with the PDF/X-3 format. Unfortunately we have not been able to narrow down specifically what is causing these errors as I have seen successful uploads from Scribus in the past, our current best guess is the font encoding that Scribus does. Are you able to outline these fonts rather than embed them and try uploading again?" - I'm using TTFs which are completely embedded in the PDFs.
And in a recent test even a PDF without any text/fonts failed, seems to be some complexity issue, as removing some pictures, even just a single picture could cause the test PDF to be accepted. PDF size is around 400+ MB.
I'd really love to get to the root cause, in various tests I wasn't able to nail it down.
Any ideas, anyone? I'd rather avoid having to shell out the money for Indesign. Thanks.