A MOBI file can contain two formats inside of it: the old MOBI KF7, and the newer MOBI KF8.
Most illustrated books require the newer formatting options available in the KF8 format, to ensure the book looks just as pretty on a reader’s Kindle as it looks on your monitor when you are creating it. You want to check the KF8 box when you upload your illustrated books to BookFunnel so that MOST of your Kindle readers will see your images correctly. One important exception: Kindle For iOS.
Kindle For iOS MIGHT NOT display your illustrated book correctly because it WILL NOT open the KF8 MOBI format. It will only display the older mobi format KF7, which isn’t always “illustration-friendly.” This is a limitation in the Kindle For iOS app when books are sideloaded (meaning, distributed outside of their Kindle Store) and Amazon hasn’t fixed it. Because the Kindle For iOS app won’t show your KF8, an illustrated book might appear blank in the Kindle For iOS app if the formatting in the KF7 format is busted. You can test your MOBI if you have an iOS device by emailing yourself the book and attempting to open it in your Kindle For iOS app.
What to do if Your Illustrated Book is Busted
If you check your MOBI in the Kindle For iOS app and it is busted, don’t panic. 🙂
We recommend iBooks when readers contact us in support, as it can perfectly download and display the illustrations. If you would prefer your readers access the book in their Kindle app, you can edit your book on BookFunnel and check the box on your Book Details page to compile your MOBI from your EPUB. Learn how to edit your book details here. Your EPUB can usually make a legible MOBI file, so Kindle For iOS readers will be able to see your images and read the book. The MOBI formatting will not look as lovely as your original book, but it should create a functional book.