title_body: Problems with ePub for iPad I am formatting an ebook for a client who is quite particular about how it looks and displays on the device he uses, a newer iPad with Retina display. One of which I, unfortunately, do not have.
  
  The current version of the ePub seems to display correctly in Calibre and ADE, my test apps, and it validates in my XML editor and the IDPF ePub validator. However, there are two glitches that show up only on the iPad: an extra blank page or two before a new chapter (sometimes but not always) and a cover image that works as a cover but is not picked up by the thumbnail-generating software. The book shows up on his iBook shelf with a generic cover. 
  
  One formatter over at Mobileread insists that he has tried many schemes to get rid of the blank pages and has given up. I think I give up too. I don't see what in my code, in the page-break-before:always that is part of the chapter .css, should be problematic. The client is willing to accept that the iPad just does that but ...
  
  He wants the cover to be resized for a thumbnail. He sent me an InDesign epub that he said displayed properly as a thumbnail and a cover. So far as I can tell, my code is the same, save that I use a .jpeg file extension rather than .jpg for the image. The .jpg would not pass the IDPF validator. Also, I kept my cover .jpeg rather modest. It's 689x1000; his is 1890x2775. I think that is much larger than generally recommended. 
  
  (Peeve: ebook cover size recommendations are all over the place. I cannot figure out who to trust on this. I do not want to craft for one device and mess up the cover for other devices.) 
  
  I would appreciate hearing from someone else who has run into these problems, or at least one of them, and has come up with solution(s).
upvoted_answer: For iBooks issues, your best bet is to go straight to the iBooks Asset Guide, which is available when you log in to your iTunes Connect account. As far as cover size goes, the guide says:
  
  
    The book’s cover art must use RGB color mode and should be at least
    1400 pixels along the shorter axis. For best results, a good rule of
    thumb is to use an image that is a minimum of 300 dpi.
  
  
  This applies to the cover art that is submitted along with the book, not the cover in the book itself. For the cover in the book (and for any other image in the book, for that matter):
  
  
    Images (within the EPUB) cannot exceed 3.2 million pixels. Apple
    recommends providing images that are at least 1.5 times the intended
    viewing size up to a maximum of 3.2 million pixels. You can calculate
    whether an image inside the book file exceeds 3.2 million pixels by
    multiplying the height of the image with the width.
  
  
  Assuming that you're creating an epub 3.0 file, if you add properties="cover-image" to the &lt;manifest&gt; entry for the cover image file, the cover will show up in iTunes.
  
  As far as extra blank pages go: you shouldn't need any page-break-before: always statements to break your chapters, assuming that you've followed best practices and broken the content into one xhtml file per chapter. iBooks and all other reading systems I've seen will automatically break pages for each new file.
  
  What errors specifically did you get that went away when you changed the extension of the cover image? Without seeing anything, my guess would be that there was a difference between how the file was named and what it was called in the &lt;manifest&gt;.
  
  Finally: if you're going to be doing ebook conversions, you really need to have the devices you're converting for&mdash;every reading system has strange quirks, and you're doing your clients a disservice if you don't test, particularly on devices that you know they're really interested in.