Why print files get rejected, and how to not be rejected
A printer's upload check is software measuring your file against a spec. It is not reading your book and it is not looking at your design. It measures, compares, and either lets the file through or stops it. That makes rejections predictable. Here are the causes, most common first.
1. The cover PDF is the wrong total size
The biggest one by a wide margin, and it is almost never the front cover that is wrong. It is the spine.
A wrap is front + spine + back + bleed, so a spine computed from the wrong page count or the wrong paper makes the whole file the wrong width. The printer checks your dimensions against the page count you declared, the arithmetic disagrees, and the upload stops.
Fix: finish the interior, take the real page count, and compute the spine from it on that printer's paper. Cream and white bulk differently, and every printer's stock bulks differently again. How to calculate spine width →
2. No bleed, or art that stops at the trim line
Printers cut through a stack with a tolerance of roughly a sixteenth of an inch, so art ending exactly at the trim line will, on some copies, end a hair short of it — a thin white sliver down one edge.
Fix: extend the artwork 0.125 inches past the trim on all four outside edges. Not stretched edge pixels: real image.
3. Live text or a barcode in the bleed, or too close to a fold
The bleed gets cut off, so anything you care about sitting in it is gone. Folds are worse: one landing a millimeter off puts the last letter of your title around a corner.
Fix: keep text, logos and the barcode 0.25 inches inside the trim and 0.125 inches clear of each fold.
4. Fonts not embedded
The printer does not have your fonts. If they are not inside the PDF, the renderer substitutes something else and your title prints in a default face — or the check catches it and refuses the file.
Fix: embed everything, or outline the type. Watch for exports that embed most fonts and miss one, usually a stray space set in a font you deleted.
In the Cover Maker. The spine comes from your real page count, paper color and printer; trim, bleed and safe-area guides are drawn live; title and author stay live vector text; and the barcode area is reserved rather than guessed at. Start a book → · about the Cover Maker
5. The interior page size doesn't match the cover's trim
You built a 6 × 9 cover and the manuscript PDF is US Letter. The two files are checked against each other, and a mismatch fails both.
Fix: set the trim size once, at the start, and use the same number in both files. Choosing a trim size →
6. An odd final page count
Books print on sheets and every sheet has two sides, so the final count has to be even. An odd one is either rejected or silently padded with a blank page somewhere you did not choose.
Fix: end on an even number yourself, so you decide where the blank goes.
7. Images below the resolution floor
Print needs roughly 300 DPI at final printed size. A 1000-pixel-wide image across a 6-inch cover is 167 DPI, and it looks soft in a way no screen preview shows you.
Fix: check the effective DPI of each image at its final size, not the pixel count in isolation. Artwork resolution for print →
8. A color page in a black-and-white book
Usually an ornament or a photo that looks gray but carries a faint cast, so it counts as color. One such page moves the whole book into color printing, which changes the price, or gets the file refused.
Fix: convert interior images to true grayscale rather than trusting your eye, and set the ink for black-and-white output.
9. Spine text on a book too thin to carry it
KDP refuses spine text on a book under 80 pages, and other printers set their own floor. There is not enough width for a legible line, and the fold wanders enough copy to copy that it would show.
Fix: below the threshold, leave the spine blank. Art running through it is still fine.
10. Front and back uploaded as separate files
A print cover is one wrap: back, spine and front on a single page, left to right. Two files is not a smaller version of that. It is the wrong thing.
Fix: export a single wrap PDF at the dimensions the printer specifies.
Hard rejection versus soft acceptance
A hard rejection is the good outcome. The upload fails, you fix it, you try again. It costs an hour and nothing else.
The expensive failure is a file that passes. Automated checks catch arithmetic, not intent. A spine 2 mm narrow, a title 3 mm from the fold, a slightly soft image — all of these sail through and come back as a print run you cannot sell.
Every printer checks different things
Passing at one printer is not passing at another. They use different bulk figures, bleed requirements, minimum page counts and spine-text rules. A file KDP accepts can be refused by IngramSpark on the same manuscript.
And none of them check design. A cover can clear every technical test and still be unreadable at thumbnail size.
In the Cover Maker. One design re-cuts for every printer and binding you need, up to eleven wrap files, and artwork below the print resolution guideline is flagged before you export — anything under 200 DPI gets called out. Start a book → · about the Cover Maker
The sequence that prevents almost all of it
Finish the interior. Take the real, final page count. Build the cover from that number, for that printer's paper. Preflight the file. Then order one physical proof before you announce anything.
In that order, most of this list cannot happen to you.
Make yours
Everything here is built into the tools, and they are free to use: name your book, bring your manuscript or your artwork, and work as long as you like. You only pay when you want the files without the preview watermark.
Next: Where to print · More: Book cover dimensions, start to finish · How to format a book interior