Originally Posted by johnleo
Didn't run through all these posts but I come across this problem all the time and thus give up trying to use it.
Does everyone's font sizes modification work properly?
After I changed those default font sizes, some of the them will not be applied when reading a book. For example, choosing 15 will give me the same font size as 16. And some other font sizes also won't work. Is it just me or is there anybody else? How can I solve this problem?
I think you'll find that the problem you describe is only evident with azw3 books.
I don't understand all the technicals, but azw3 uses a different "system" (ie, not Java) for displaying the books that you are reading, and hence you are limited to the default font sizes, no matter what sizes you have specified in JBPatch. If the default sizes are (making up numbers here) 7, 9, 13, 16, 25 and 31, and you specify 9, 11, 15, 21 and 31 in JBPatch, the only ones you'll be able to use will be 9 and 31. Trying to select any of the other sizes won't do anything.
If you were to re-encode the books you're having issues with as mobi files, you will find that all of the font sizes you have specified in JBPatch will work.
The other alternative is to use something like calibre and embed the font sizes in the book this way. I have not done this, so I don't know if it works or not. I simply convert all my azw3 files to mobi (using calibre) and I have full control over the font sizing on the Kindle.