I am trying to use the calibre conversion feature to convert ebook written in Georgian from PDF to Mobi. The effect is however very poor. Someone in 10 lines gets unwrapped. I tried to use different unwrapping factors but to no avail. I tested this feature on a Polish book and the effect was satisfactory with default settings.

Important note about Georgian – its script is unicameral. So I suspect that the lack of capital letters at the beginning of the sentences can cause the unwrapping algorithm to fail. But I didn't look at the code, so maybe someone who knows the algorithm better could confirm.

So my questions are:

  1. Can it be the unicameral character of the alphabet that causes the problem?
  2. Can I tweak the algorithm to fix it?
  3. Is there any other conversion tool that could work for me here.
  • Calibre will usually produce better results, if you activate all Heuristics options. (Preferences > Common Options > Heuristic Processing.)
    – user4665
    Commented Mar 7, 2018 at 20:46
  • As stated in my question, I activated them and even tried several unwrapping factor settings.
    – zefciu
    Commented Mar 9, 2018 at 7:51

2 Answers 2


I have checked the source code and it turns out that Calibre doesn't support non-latin script at all. The bug was filed here: https://bugs.launchpad.net/calibre/+bug/1753533 the developer, however, refuses to use Unicode data to recognize alphabetic characters. Mkhedruli was added, but if you want other alphabets to be supported, you either need to manipulate the source code or file another bug.


A. Thanks, Nemo; I was having difficulty with Calibre, too. B. I find that Kotobee Author (free) preserves my fonts when uploading a completed project. When building the ebook inside Kotobee, according to the help section 'Knowledgebase,' authors can also apply Google fonts to their projects. It will require linking to the font via the Google API within the Global CSS file in Kotobee Author. I'm making this sound a lot more complicated than in the actual application.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.