Originally Posted by Ripplinger
But now I was wondering if that "old" format type is compatible with newer Kindle readers. I don't want to be restrictive in what readers can view books after I've gone to all the trouble of scanning and editing.
Is setting the mobi type to "old" ok? Or would it be better to set it to "both" regardless of the file size it turns out? Or maybe a different program for the conversion for those odd books that seem to jump oddly in size, it doesn't happen on all books.
The new Kindles can read MOBI6 files (the 'old' setting) just fine; no problem there. However, KF8 has more potential capability for layout, much like ePUB.
That combined MOBI6/KF8 files (the 'both' setting) are larger is to be expected, as they are essentially both files in a single wrapper.
For KF8-supporting Kindles as primary target, I'd set the format to 'both' and let the bytes fall where they may.