A KDP interior has the same page size on IngramSpark. IngramSpark still asks for a PDF/X file and for wider margins than KDP's minimum. Lulu adds bleed on all four sides, so its page is a different size.
The cover has to be laid out again for each platform, because each one sets its own spine width.
The interior
For a 6 × 9 inch book:
| KDP | IngramSpark | Lulu | |
|---|---|---|---|
| Page size without bleed | 6 × 9″ (152.4 × 228.6 mm) | 6 × 9″ | 6 × 9″ is accepted, and Lulu adds the bleed as white |
| Page size with bleed | 6.125 × 9.25″ (155.6 × 235 mm) | 6.125 × 9.25″ | 6.25 × 9.25″ (158.8 × 235 mm) |
| Bleed on | Top, bottom and outside edge | Top, bottom and outside edge | All four edges |
| Margins | Outside at least 0.25″, or 0.375″ with bleed; inside 0.375″ to 0.875″ by page count | 0.5″ recommended on every side | 0.5″ safety margin; inside 0.5″ to 1.25″ recommended by page count |
| PDF standard | PDF/X-1a preferred, other PDFs taken | PDF/X-1a:2001 or PDF/X-3:2002 required | None named; Lulu publishes its own export settings |
| Not wanted in the file | Crop marks, trim marks, comments | Crop marks, ICC profiles, spot colors | Trim and bleed marks |
A KDP file without bleed is already the size IngramSpark asks for, and a KDP file with bleed matches IngramSpark's bleed size. What may have to change is inside the page.
KDP allows an outside margin of 0.25″. IngramSpark recommends 0.5″ on every side, because its printing can vary by 1/16″. Text closer to the edge than that can be cut.
IngramSpark's guide also requires a PDF/X-1a:2001 or PDF/X-3:2002 file. KDP only prefers PDF/X-1a, so a file made for KDP may need exporting again. IngramSpark keeps the last page blank for its production details, and adds blank pages where the count needs them.
Lulu prints every book with 0.125″ of bleed on all four edges. A file at the plain trim size is accepted, and Lulu fills the missing bleed with white. Its Book Creation Guide recommends that for a book with nothing at the edge, while its help page asks for the bleed size in every case.
A KDP file with bleed is 0.125″ narrower than Lulu's size, because KDP adds no bleed at the spine edge. It has to be set up again for Lulu.
The cover
The same artwork can serve all three platforms. The same PDF cannot, because the spine width differs and each platform has its own template.
| KDP | IngramSpark | Lulu | |
|---|---|---|---|
| Spine of a 300-page paperback | 0.676″ (17.2 mm) on white paper, 0.75″ (19.1 mm) on cream | Drawn on the template made for your book | 0.736″ (18.7 mm) |
| Template | A calculator and template generator, not required | Required, from its Cover Template Generator | From its Pricing Calculator, or made when the interior is uploaded |
| Bleed | 0.125″ | 0.125″ | 0.125″ |
| Marks | Crop marks and template text removed | Artwork placed within the template's crop marks | No trim or bleed marks |
| Spine text | From 79 pages | From 48 pages | Not at 80 pages or fewer |
| Barcode | Added by KDP if the cover has none | On the template; it may be moved, not resized | Needed only for retail distribution |
KDP gives a thickness per page for each paper, and Lulu gives a formula: pages divided by 444, plus 0.06″. IngramSpark's guide gives neither. Its spine comes from the template it sends for your book.
On 300 pages, KDP's white paper and Lulu's formula differ by 0.06″. That moves both folds, so a cover laid out for one spine does not fit the other. Keep the front, the back and the spine as separate parts of your design file, so the cover can be laid out again on each template.
The ISBN
The ISBN is printed on the copyright page and in the barcode, so it decides whether those can stay the same. KDP says of the ISBNs it gives away: “Free ISBNs from us can only be used on KDP.” A book that has one needs another ISBN elsewhere, and new files with it.
IngramSpark sets up a print book on an ISBN you own. It asks that the same book not be enrolled in KDP's Expanded Distribution.
What each platform's upload check looks at
KDP's Print Previewer checks margins, cover size and fonts, among other things, and may scale or reflow text to fit the margins. IngramSpark rejects a file whose fonts are not embedded. Lulu looks for the bleed on each edge, adds it as white where it is missing, and shows a warning.
None of these checks prints the book. A proof copy from each platform shows what its press does with the files.
Other print services
Each service publishes its own rules. tolino media, for example, reports a missing TrimBox or BleedBox in a print PDF even when the page size is right. It advises setting the bleed in the layout program rather than enlarging the page by hand.
What Torcul does
Torcul makes the interior and the cover to KDP's measurements. Its interior margins are at least 0.5″ on every side, as IngramSpark recommends.
Its PDFs are not PDF/X files and carry no TrimBox or BleedBox, and its cover uses KDP's spine width. For IngramSpark, Lulu or tolino they need the changes above. The free PDF checker and cover checker test a file against KDP's rules only.
Sources
- KDP: Set Trim Size, Bleed, and Margins
- KDP: Save Your Manuscript File
- KDP: Paperback Submission Guidelines
- KDP: Create a Paperback Cover
- KDP: Fix Paperback and Hardcover Formatting Issues
- KDP: What is an ISBN and Imprint?
- IngramSpark: File Creation Guide (dated 24 August 2026)
- IngramSpark: Frequently Asked Questions
- Lulu: What is Full Bleed?
- Lulu: PDF Creation Settings
- Lulu: Book Creation Guide
- tolino media: Trim-Box and Bleed-Box errors (in German)
None of this guarantees that a platform will accept a file. All three change their guides, so compare the date on this page with theirs.