Publishing.
Glossary

The area of your cover design that extends beyond the final trim line. KDP requires a 0.125 inch (3.18 mm) bleed on all sides to ensure the cover image fills the page to the edge after trimming. Any design element you want to appear at the very edge of the printed cover must extend into the bleed zone.

The final physical dimensions of your printed book after the manufacturing process cuts the pages to size. Common trim sizes include 5×8", 5.5×8.5", and 6×9". Your cover template and interior formatting must match your chosen trim size exactly.

The thickness of the book measured at the binding edge. Calculated by dividing your total page count by the PPI constant for your paper stock. The spine width determines the space available for your title and author name on the spine panel of the cover.

The inner margin of the cover design that is guaranteed to remain visible after trimming and binding. KDP recommends keeping all text and important imagery at least 0.125 inches inside the trim line to avoid elements being cut off or disappearing into the spine fold.

The inner margin of an interior page adjacent to the binding. Pages bound into a book cannot lie perfectly flat, so the gutter must be wide enough to keep text readable when the book is open. Longer books require a wider gutter to prevent text from disappearing into the spine crease.

The number of pages of a specific paper stock that stack into one inch of spine thickness. KDP uses three constants: 444 PPI for white standard paper, 435 PPI for cream premium, and 480 PPI for colour stock. PPI is the essential variable in the spine width calculation.

The tendency of printed spine content to shift sideways during binding due to manufacturing tolerance variance. KDP operates with a ±0.0625 inch (1.6 mm) tolerance. Designing spine text too close to the fold lines risks it drifting onto the cover panels in the finished book.

The precise alignment of printing elements on both sides of a page and across the cover. Poor registration causes text to show through from the reverse side or causes cover elements to appear misaligned relative to the book block.

Cyan, Magenta, Yellow, Key (Black) — the four-ink colour model used in commercial printing. All print-ready cover files must be converted to CMYK before submission. RGB colours converted to CMYK may shift, particularly vibrant blues and greens which fall outside the CMYK gamut.

Red, Green, Blue — the colour model used for screen displays. Digital images created in RGB must be converted to CMYK for print. Colours that appear vivid on screen often appear muted in print, and the conversion should be checked carefully before finalising cover artwork.

The resolution of a printed image, measured by the number of ink dots placed per linear inch. KDP requires cover images at a minimum of 300 DPI at the final print size. Images that look sharp on screen are often only 72–96 DPI and will appear blurry or pixelated when printed.

A PDF standard designed for reliable commercial printing. It ensures fonts are embedded, colours are in CMYK, and the file contains no transparency. KDP accepts PDF/X-1a as the preferred format for interior and cover files, reducing the chance of print errors caused by unsupported elements.

KDP's default paper stock for black-and-white interiors. 55 lb weight, 444 PPI. The most affordable option and the standard choice for most non-fiction books, textbooks, and commercial fiction.

KDP's warmer-toned paper stock. 60 lb weight, 435 PPI. Slightly thicker per page than white standard, producing a wider spine at the same page count. The traditional choice for literary fiction and poetry, producing a softer reading experience.

A printed sample of your book produced before final publication is approved. Reviewing a physical proof is the most reliable way to verify spine width accuracy, colour reproduction, paper quality, and formatting before making the book available for sale.

The standard binding method for paperback books, where pages are glued directly to the cover spine using hot adhesive. This is how KDP produces standard paperback editions. The spine must be wide enough to hold the adhesive reliably — typically a minimum of 80 pages on white paper.

A binding method where folded sheets are stapled through the spine. Used for booklets, magazines, and pamphlets typically under 64 pages. Not available through KDP Print, which uses perfect binding for paperbacks.

A hardcover binding style where printed cover material is glued to a rigid cardboard case. KDP case laminate hardcovers require adding 0.063 inches to the calculated spine width to account for the board thickness. The most common hardcover option on KDP.

A hardcover style where the cover image is printed directly on material that wraps around the boards without a separate dust jacket. No additional spine width allowance is needed for image wrap beyond the page-count-based calculation.

Amazon's self-publishing platform for print and digital books. KDP Print handles paperback and hardcover production in the US, UK, and other markets. Books published via KDP are available on Amazon directly and, through expanded distribution, at other retailers.

Ingram Content Group's self-publishing platform. Offers access to a distribution network of 40,000+ retailers, bookstores, and libraries worldwide. Requires a setup fee per title but provides broader retail reach than KDP's expanded distribution, including returns-accepting bookstore supply chains.

A unique 13-digit identifier assigned to each edition and format of a book. Required for distribution through most retail channels. KDP provides free ISBNs, but using a KDP-provided ISBN lists KDP as the publisher of record. Authors who want to list their own imprint must purchase their own ISBN.

A printing model where books are printed individually as orders are placed rather than in large pre-printed batches. Both KDP and IngramSpark operate on POD. This eliminates inventory risk but results in higher per-unit printing costs than traditional offset printing.

KDP's distribution network beyond Amazon.com, allowing books to appear at other online retailers and in library catalogues. Expanded distribution applies a 40% wholesale discount, reducing per-copy royalties but increasing retail reach without additional work from the author.

The amount an author earns per copy sold after platform fees and printing costs are deducted. For KDP paperbacks: Royalty = (List Price × 0.60) − Printing Cost for expanded distribution sales. The 0.60 multiplier reflects KDP retaining a 40% wholesale discount.

The per-copy cost KDP charges to produce a paperback. Calculated as $0.85 (base rate) plus $0.012 per page for black-and-white US editions. Printing cost is deducted from gross revenue before calculating the author royalty.

The percentage of the list price that KDP retains for its distribution and retail services. KDP's standard wholesale discount is 40% for expanded distribution, leaving 60% of the list price as net revenue before printing costs. Direct Amazon sales carry a higher net percentage.

The retail price set by the author for their book. Must exceed the minimum threshold (printing cost divided by 0.60) to generate a non-negative royalty. Setting a list price near the minimum leaves almost no profit margin per copy sold.

The minimum list price at which an author earns a zero royalty — no profit, but no loss. For KDP expanded distribution: Printing Cost ÷ 0.60. Books priced below this threshold produce a negative royalty, which KDP prevents by blocking submissions below the minimum.

The total number of pages in the finished interior PDF, including all blank pages. Every page — blank chapter ends, title page, copyright page, table of contents — contributes to the spine width calculation. Use the final page count from your formatted PDF, not an estimate from your word processor.

The pages at the beginning of a book before the main content, including the title page, copyright page, dedication, table of contents, foreword, and preface. Front matter pages count fully toward the total page count used in spine calculations.

Content at the end of a book after the main text, including appendices, bibliographies, indexes, author biography, and acknowledgments. Like front matter, back matter pages are included in the total page count.

The complete interior of a printed book — all the bound interior pages — before the cover is applied. The physical thickness of the book block determines the spine width and governs the cover template dimensions.