Guides
Coloring book trim sizes, margins and bleed on KDP
Trim size is the first decision in the interior file and the hardest to change later, because margins, cover width and printing cost all follow from it. For coloring books the answer is usually 8.5 x 11 inches, and the reasons are practical: buyers expect that size, art drawn for it does not need re-laying out, and a full-page subject has room to breathe. Here is when to pick something else, and what the margins have to be.
The sizes worth considering
| Trim size | Good for | Watch out for |
|---|---|---|
| 8.5 x 11 in (216 x 279 mm) | The default. Kids and adult line art, one full-page subject per page, the size buyers picture when they read "coloring book". | Nothing. Start here unless you have a specific reason not to. |
| 8 x 10 in | A slightly smaller book that still reads as a coloring book and costs a little less to print. | Art has to be re-laid out. Shrinking an 8.5 x 11 page leaves the margins wrong. |
| 8.5 x 8.5 in (square) | Toddler books and gift books. Stands out on a shelf and in a hand. | Not available in every KDP marketplace, and the thumbnail looks unusual next to portrait covers. |
| 6 x 9 in | Pocket mandala or travel books meant to be carried. | Too small for detailed adult art. Fine lines crowd together and print muddy. |
| A4 (8.27 x 11.69 in) | European buyers who print an Etsy file at home. | For KDP, letter prints in more marketplaces. Keep A4 for the printable version only. |
Margins: the gutter is what ruins coloring books
Every paperback loses part of the inside edge into the spine. On a novel that costs you a few millimetres of text. On a coloring book it means the buyer cannot lay the page flat to color the left third of the drawing. KDP sets a minimum inside margin that grows with the page count, and a minimum outside margin.
| Interior page count | Minimum inside (gutter) margin | Minimum outside margins |
|---|---|---|
| 24 to 150 | 0.375 in | 0.25 in |
| 151 to 300 | 0.5 in | 0.25 in |
| 301 to 500 | 0.625 in | 0.25 in |
| 501 to 700 | 0.75 in | 0.25 in |
| 701 to 828 | 0.875 in | 0.25 in |
Treat those as the floor, not the target. For a coloring book, give the inside edge 0.75 in and the other three edges 0.5 in. The drawing gets a white border, which colorists like anyway, and nothing important disappears into the spine.
Bleed or no bleed
No bleed means the art stops before the trim edge and the page has a white border. Bleed means the art runs off the edge, so you build the PDF slightly larger than the trim size and Amazon cuts through the artwork.
- No bleed is right for almost every coloring book. A full-page drawing with a white margin is easier to color, easier to lay out, and safe against the millimetre of cutting variance that print on demand has.
- Bleed is worth it when the page is a background pattern that should not end in a visible white frame, such as a dense floral or a full-page mandala meant to fill the sheet. For an 8.5 x 11 trim, the bleed document is 8.625 x 11.25 in: 0.125 in added on the outside edge and on the top and bottom.
- Never mix the two in one interior file. KDP applies one setting to the whole book.
What changes if you pick a different size
- Printing cost: bigger pages cost more per page, and the cost is deducted from every sale. The KDP printing cost calculator gives the current number for your size, page count and marketplace.
- Cover wrap: the full cover PDF is sized from trim plus spine plus bleed, so a new trim size means a new cover file. Download a fresh template from the KDP cover calculator.
- Availability: some sizes are not offered in every marketplace or in expanded distribution. KDP tells you at upload, which is late.
Decide once, then build the template
Set up one blank page at your trim size with your margins drawn as guides, and export every drawing into that template. It sounds obvious and it is the step people skip, which is how books end up with page 14 sitting 4 mm lower than page 13. If your pages come out of a generator, check the first and last page against the template before you upload the whole file.
Frequently asked questions
Is 8.5 x 11 in the same as A4?
No. A4 is narrower and taller (8.27 x 11.69 in). Letter is the safer choice for KDP; keep A4 for a printable sold to European buyers.
Can I change trim size after publishing?
Not on the same listing. You upload a new interior and cover as a new edition, which loses the reviews. Choose carefully the first time.
Do I need bleed for a full-page drawing?
Only if the drawing is meant to run off the edge. A full-page subject with a white border is a no-bleed page and is the normal choice.
What margin should the drawing itself have?
Give the art 0.5 in on three sides and 0.75 in at the spine. That is above KDP’s minimum and keeps the page colorable when the book is open flat.
Does trim size affect the royalty?
Indirectly. The royalty is a percentage of your list price with the printing cost deducted, and the printing cost depends on trim size and page count. Run your numbers in KDP’s calculator.