NOOK File Formats: EPUB and PDF - dummies

By Corey Sandler

The NOOK Color and the NOOK Simple Touch work with files created using one of two eBook formats: EPUB or PDF. Formatted books refer to manuscripts that have been set in type with an attractive and logical design, organized into chapters, and often supplemented with icons, illustrations, and images.

Here is just enough about eBook formatting:

  • EPUB pages are reflowed, which means the lines of text will break differently as you change the size of the text.

  • Reflowable PDFs act the same as EPUB files.

  • Non-reflowable PDFs don’t shift pages.

EPUB files for NOOK eReaders

The EPUB format is free and open, meaning that anyone can produce and distribute a file using this standard. Free and open does not mean that someone can release to the world a document based on copyrighted material that belongs to someone else. It also does not mean that someone can make free copies of all files and openly distribute them.

An EPUB file is reflowable, meaning that the text can be fine-tuned to the demands of nearly any electronic reader or to the personal preferences of any human reader: typefaces can be changed, their size adjusted, and other attributes modified. Without getting too deep into the digital weeds here, the EPUB format is a variation of the coding used to produce text displayed on web pages.

EPUBs work well with text that can easily be reflowed; not so well with graphic content like comic books and magazines.

There are two basic types of EPUB in use: protected and unprotected.

Unprotected EPUBs are commonly used for distribution of books that are no longer under copyright. (That’s why you’ll see hundreds of free versions of books by Jane Austen, Mark Twain, Jules Verne, Charles Dickens, and other literary greats.) You can use the same format to display personal documents on the screen of an eReader if you use a specialized utility to convert a word processing or spreadsheet file to the EPUB format.

Protected EPUBs include Digital Rights Management, encoding intended to limit the use of the file to a single purchaser, an individual machine, or to set a time limit. The process of borrowing a book from a library shares some of the same restrictions.

Most of the electronic books you purchase from Barnes & Noble or other commercial websites are going to be protected EPUBs. After all, they don’t want someone out there—not you, of course—buying a single copy of a book and then sending it by email to a few million of their closest friends.

EPUBs are currently used by the NOOK Color, the NOOK Simple Touch, the Sony Reader, the Kobo eReader, the Apple iPad, and a number of other devices. Noticeably missing from that list: the Amazon Kindle, which uses a proprietary format for its protected files.

PDF files for NOOK eReaders

The Portable Document Format was created by Adobe Systems all the way back in 1993 as a means to allow users to exchange documents without worrying about whether the hardware and software at each end matched. It was let loose on an unsuspecting and ultimately grateful world in 1998 as an open and free standard.

PDF files can contain embeded fonts and images, and pages can be enlarged. It’s a great way to send a complex document for display on standard sizes of personal computers. The reader on one device will see a “page” that is identical or highly similar to the one seen on another device.

At first, PDF files were not particularly well suited to the smaller and non-standard screens of devices like smartphones and digital readers because the pages were not set up to reflow text if character size was changed. But enhancements by Adobe now permit files to be reflowable (essential for eReaders with changeable typefaces, type sizes, line spacing, and margin adjustments).

Just as with EPUBs, there are both protected and unprotected versions of PDF files. An unprotected version is intended to be redistributed more or less without restriction. If you use a word processor or other productivity program on your laptop or desktop computer, you should be able to save files as unprotected PDFs. You will also find on the Internet some book files available in that open format.

A protected version uses Digital Rights Management to enforce some level of control over copying, transferring, printing, and other actions.

For more information about the NOOK eReader and its features, explore NOOK eReaders For Dummies, Portable Edition.