Artwork or colour that runs past the edge of the page, so nothing white shows after the paper is trimmed. On KDP paperbacks, bleed extends 0.125 inch (3.2 mm) beyond the trim on the top, bottom, and outside edges. Any image meant to reach the page edge needs it — see KDP Print Paperback.

Front Matter & Back Matter

Front matter is everything before the main text: title page, copyright page, dedication, and contents. Back matter comes after it: acknowledgements, notes, index, about the author, and other books by the author. Both need consistent formatting in print and eBook editions.

Gutter

The inside margin of a printed page, next to the spine. It must grow with page count so text doesn’t disappear into the binding — KDP’s minimum runs from 0.375 inch for books up to 150 pages to 0.625 inch at 301–500 pages, and wider beyond that.

Preflight

A final technical check of a print file before it goes to the printer — trim size, margins, bleed, fonts, and image resolution. Files that fail preflight are sent back, which is why every print interior we deliver is preflighted first.

Safe Zone

The area inside the trim edge where text and important artwork must stay so nothing is cut off. On KDP, outside margins must be at least 0.25 inch without bleed and 0.375 inch with bleed.

Trim Size

The final width and height of a printed book after trimming — for example 5 × 8 or 6 × 9 inches. It sets the page layout, the page count, and the spine width, so choose it before formatting begins. See our trim size guide.

Wraparound Cover

A print cover designed as one file: back cover, spine, and front cover side by side, with bleed. The spine width depends on the page count and paper, so the wrap is finished once the interior is final — see our Cover Design packages.

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Kindle Terms

Enhanced Typesetting

Amazon’s set of Kindle reading improvements — better hyphenation, kerning, ligatures, and layout — shown as “Enhanced typesetting: Enabled” on the book page. Reflowable books built cleanly qualify; fixed layout books do not support it.

Guided View

A Kindle reading mode that moves through a comic or illustrated book one panel at a time, so pages stay readable on phones. Panels are defined when the book is built.

KDP Select

An optional 90-day programme in which your eBook is sold exclusively on Amazon. In return it is included in Kindle Unlimited, where you are paid per page read from the KDP Select Global Fund. It is also required for the 70% royalty on sales in Brazil, Japan, Mexico, and India. See our KDP Royalty Calculator.

Kindle Previewer

Amazon’s free desktop app that shows how a book will look on Kindle devices and apps. It is the standard way to check a Kindle file before publishing — every Kindle file we deliver is checked in it.

KPF

Kindle Package Format — the file format created by Amazon’s Kindle Create and Kindle Previewer tools and uploaded to KDP. It is a finished, packaged file, so text changes are made in the source (usually ePub) and the KPF is rebuilt. See Kindle Conversion.

Quality Notification

A message from Amazon telling a publisher that customers or Amazon’s checks found problems in a book — typos, broken links, or formatting errors. Unresolved issues can lead to a warning on the book page or removal from sale.

Region Magnification

The Kindle feature that lets readers double-tap an area of a fixed layout page — a block of text or a panel — to enlarge it. Amazon’s guidelines call these text pop-ups. See Fixed Layout Kindle.

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ePub Terms

Aggregator

A distributor that delivers one eBook file to many stores at once — for example Draft2Digital — usually for a share of each sale. It saves uploading to each retailer separately.

Embedded Fonts

Font files packaged inside an eBook so it displays in the typeface you chose. The font’s licence must allow eBook embedding, and some readers let the reader override it with their own font.

EPUBCheck

The official ePub validator, maintained by the W3C. Apple Books, Kobo, Google Play, and other stores check files against it, so an ePub should pass with zero errors before upload. Every ePub we deliver does.

MathML

A markup language for writing mathematical equations as real text in ePub 3, rather than as images. Support varies between reading apps, so complex maths often needs a fallback.

NCX

The navigation file used by older EPUB 2 books to build the table of contents in a reading app. EPUB 3 uses a navigation document instead, but many ePubs still include an NCX for older devices.

OPF

The package file at the heart of every ePub. It holds the book’s metadata (title, author, language), lists every file in the book, and sets the reading order.

W3C EPUB Standard

The official specification for the ePub format, maintained by the World Wide Web Consortium (W3C). The current version is EPUB 3, and it is what ePub files are validated against.

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Fixed Layout Terms

Fixed Layout

An eBook in which every page keeps its exact design — text and images locked in position, like a printed page. It suits picture books, cookbooks, and comics, but text cannot reflow or be resized. See Fixed Layout ePub.

Spread

Two facing pages seen together, left and right, as in an open book. Fixed layout books are usually designed and priced by spread rather than by page — see Children’s Book Formatting.

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Scanning & Accessibility

OCR

Optical Character Recognition — software that turns scanned page images into editable text. It misreads faded print, unusual fonts, and special characters, so the output needs human proofreading. See Book Scanning & OCR.

WCAG

The Web Content Accessibility Guidelines — the international standard for making digital content usable by people with disabilities. ePub accessibility standards build on WCAG, and the European Accessibility Act, which applies from June 2025, requires many eBooks sold in the EU to be accessible.

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Troubleshooting & Common Problems

Fake Bold/Italic

What happens when a font has no real bold or italic version and the reading app imitates one by thickening or slanting the text. The result looks smudged; the fix is to embed the font’s true bold and italic files.

Image Aspect Ratio Distortion

An image that looks stretched or squashed because its width and height were set independently. In eBooks, images should scale proportionally so they display correctly on every screen size.

Keywords (KDP Metadata)

The seven search terms you enter in KDP to help readers find your book on Amazon. Good keywords describe what readers search for — genre, themes, and setting — rather than repeating your title. See our Kindle Formatting Checklist.

Widow/Orphan

A single line of a paragraph stranded at the top (widow) or bottom (orphan) of a printed page. They look careless in print and are corrected by hand during print formatting; reflowable eBooks handle line breaks automatically.

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General Terms

Drop Cap

A large first letter that spans several lines at the start of a chapter. It is a classic print detail that can be reproduced in eBooks with careful coding so it does not break on small screens.

InDesign

Adobe’s professional page layout software, used by most publishers to design print books. InDesign files (.indd or .idml) are an excellent source for eBook conversion, because the text and styles are already structured.

ISBN

International Standard Book Number — a unique 13-digit identifier for each edition of a book. Each format (paperback, hardcover, ePub) needs its own; KDP offers a free ISBN for paperbacks, and Kindle eBooks can be published without one. See our Word templates.

Manuscript Formatting vs. Book Formatting

Manuscript formatting prepares a document for editors and agents (double-spaced, plain text). Book formatting prepares it for readers — the finished eBook or print interior. Our free Word templates bridge the two.

Metadata

The information that describes a book to stores and reading apps — title, author, language, description, categories, keywords, and ISBN. Complete, accurate metadata helps readers find your book and prevents upload rejections.

Reflowable

An eBook whose text adapts to the reader’s screen, font, and text size, like a web page. It is the standard for novels and most non-fiction. See Kindle Conversion and ePub Conversion.

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Missing a term? Tell us and we will add it. For step-by-step help, try our free resources or the FAQ.

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