Flowing and Fixed-Layout Books: Custom Page Numbers
In flowing and fixed-layout books, <pageList> can be used to define the page numbers that iBooks assigns to each page. For example, the first page of the book is page 1 by default, but in some books, this may be the cover page and shouldn't be numbered. You can use <pageList> to define an empty string to that page so that it is not numbered. Similarly, you can define Roman numerals (i, ii, iii), letters (a, b, c), or numbers (1, 2, 3) for page numbers. If you use something other than numbers or a single word, make sure it is meaningful, keep it very short, and check to make sure it doesn't get truncated on the device. Using <pageList> requires iBooks 2.1 and newer.
Multi-Touch Books for iPad
Added a new chapter to describe best practices and asset requirements and encoding for Multi-Touch books for iPad. Multi-Touch books require iBooks 2.0 or later, iOS 5.0 or later, macOS X 10.7.3 Lion or later, and iTunes 10.5.3 or later.
NCX File Clarifications
For optimal customer experience, Apple requires the navMap element in the NCX. iBooks uses the data provided in the NCX to build the customer-facing table of contents. The navMap element must contain one or more navPoint elements. Each navPoint creates an entry in the table of contents. However, if the navMap contains only one navPoint, iBooks suppresses the list table of contents, which could be useful when creating fixed-layout books. For example, a picture book does not need a list table of contents as it does not have chapters. iBooks will always create a thumbnail table of contents for a fixed-layout book.
Images: Best Practices
When testing your book, be sure to preview it in night mode (the Night option under Theme). The Night reading theme makes reading books in the dark easier on the eyes. In night mode, the transparent areas of an image will be black. If your image has dark text within a transparent image, that text could be difficult to read in night mode. Instead, we suggest you use a JPG with a white background.
We recommend providing images that are at least 1.5 times the intended viewing size up to a maximum of 2 million pixels (image height multiplied by image width should be less than 2,000,000px). For example, a single-page, full-bleed image should be around 1200px by 1600px.
Links
When setting up a link to a book on iBooks, use itms-books:// instead of http:// at the beginning of the URL. This takes the readers directly to the book on iBooks without first displaying a message that they're leaving the iBooks app. See Linking Directly to Your Book in Apple Books for more details.
Flowing Books: Font Best Practices
Font sizes should be defined in ems (em) or pixels (px), not by name, for example, small or large. The main text of a book should either not have a defined font-size or should have a font-size of 1em. This will ensure ideal readability and font scaling.
Read Aloud Books
Read Aloud Books require a custom preview. See Samples for Read Aloud Books.
Screenshot Requirements
Screenshots must be full-sized iPad 1/2 images (1024 x 768 or 768 x 1024) or full-sized new iPad images (2048 x 1536 or 1536 x 2048) in PNG (.png) or JPEG (.jpg) format. For a cleaner look, you can optionally remove the status bar (making the images 1004 x 768 or 748 x 1024 for iPad 1/2, or 2028 x 1536 or 1536 x 2028 for the new iPad). Note that screenshots can only be provided when the book is first delivered.
Adobe Creative Suite 5.5 Error Fix
The Adobe Creative Suite 5.5 bug that resulted in XHTML errors in EPUBs exported by InDesign has been fixed. If you have encountered this problem using InDesign CS5.5, apply the 7.5.2 update and regenerate the EPUB file. You can find the update here: https://www.adobe.com/downloads/.