The paperback cover is one PDF: back cover, spine and front cover side by side, with bleed all around. Its width depends on the trim size, paper and page count.
File rules
Pictures at 300 DPI.
Single PDF
Flattened transparency
Embedded fonts
No crop marks
No security
No spot colors
Text at least 7 pt.
Under 40 MB is recommended; 650 MB is the limit.
Safe areas
0.125 in bleed on every outside edge.
Keep text 0.125 in inside the trim and 0.0625 in from the spine folds.
Leave a 2 × 1.2 in area free on the back cover, 0.25 in from the bottom and spine-side edges, for the barcode KDP adds.
Spine text
KDP allows spine text only on books with more than 79 pages (80 or more). Thinner books get a plain spine.
Sources
KDP help pages, checked November 7, 2026. KDP changes its rules without notice; the linked page has the final word.
kdpbookai
