Some books will display the cover, some refuse to at all, and some display momentarily only to disappear after a minute.
What are the requirements to get Calibre side-loaded book covers to consistently show up on a Kindle PW4 ?
- Do book formats matter (eg. mobi / azw3 / kfx) ? No.
- Do book ids matter (eg. must I set/unset isbn / mobi-asin) ? No.
- Do book cover sizes matter (eg. Is there a maximum resolution) ? YES!
- Under what circumstances can/does the Kindle download it's own covers from Amazon ? Unclear, probably based on book IDs.
- Must I embed the cover image somehow (eg. I've read about epub to epub conversions) ? No.