KDP Glossary  / Publishing

What is Bleed in Book Cover Design?

Bleed is the area of your book cover that extends beyond the final trim line — the line where the cover is cut after printing. Because printing and cutting machines can't be perfectly aligned on every copy, a small amount of variation exists between where the ink ends and where the cut happens. Bleed provides a buffer zone so that even if the cut is slightly off, no white edges appear on the finished book.

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How much bleed does KDP require?

KDP requires 0.125 inches (approximately 3.2mm) of bleed on all four sides of a paperback cover. This means your cover file must be larger than the final trim size by 0.25 inches in both width and height (0.125" added to each side). For a 6" × 9" paperback, your cover file must be at least 6.25" × 9.25" before the spine width is added. Any design elements that are intended to reach the edge of the finished cover — background colour, photos, patterns — must extend all the way to the bleed edge, not just to the trim line.

Safe zone: the other side of bleed

In addition to bleed extending outward, there is a "safe zone" extending inward from the trim line — typically 0.125 inches. Important text (your title, author name, spine text) and faces in photos should stay within the safe zone. If critical content is placed between the trim line and the safe zone, it risks being partially cut off even when the trimming is technically within tolerance. Think of it as bleed out, safe zone in — your cover design lives in the space between them.

Frequently asked questions

What happens if I don't include bleed?

KDP will either reject your cover file outright or the printed book will have white edges where the background colour or image doesn't reach the cut line. White edges on a paperback look unprofessional and are a common reason for poor reviews on self-published books. Always extend background elements to the bleed edge.

Does bleed apply to eBook covers?

No. eBook covers are digital images — there's no physical trimming involved. eBook cover files don't require bleed. KDP's requirement is minimum 1000px on the shortest side, with a 1.6:1 height-to-width ratio for best display across Kindle devices.

Does bleed affect my cover template size?

Yes. Your full cover template width = spine width + (2 × trim width) + (2 × 0.125" bleed). If you're designing a 6" × 9" paperback with a 0.5" spine, your template is (0.5 + 2×6 + 2×0.125) = 12.75" wide × 9.25" tall. Use the KDP Spine Width Calculator to get these exact dimensions.

Related terms

Trim Size Spine Width KDP Proof Copy

Related niches

Coloring BooksChildren's BooksCookbooksArt & Craft Books

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