KDP Bleed and Margins: How to Set Up a Coloring Book Interior

Decide whether your pages bleed before you make a single one, because that decision changes the size of every page in the file.

With bleed, your PDF pages are 0.25 inches taller and 0.125 inches wider than the trim size you picked. Without bleed, they are exactly the trim size. There is no way to change your mind later without redoing the artwork.

That is the whole thing in two sentences. Here is what sits underneath it.

What bleed actually is

Bleed is artwork that runs past the edge of the finished page so the printer has something to cut through.

Printing is not precise to the millimetre. The pages are printed, then stacked, then trimmed. If your artwork stops exactly at the edge and the blade lands a hair inside it, you get a thin white sliver down the side of the page. Extending the artwork past the edge means the blade always cuts through ink, and the color runs right off the paper.

So it is not a quality setting or a checkbox you tick to make the book better. It is an allowance for the blade.

Does a coloring book need it?

Only if your pages have something running to the edge.

Line art sitting in the middle of a white page does not bleed. Most coloring books look like that, and those files are set up at the plain trim size with no bleed at all. This is the simpler route and there is nothing second-rate about it.

Your pages need bleed if they have a background color, a border that reaches the edge, a full-page illustration, or a decorative frame. If you are working through how to publish a coloring book on Amazon, this is the decision to make at the same moment you pick your trim size, because the two numbers are calculated together.

One rule catches people who mix the two. If any page in the book needs bleed, the whole file is set up with bleed. You cannot have one full-page illustration in a book of centered line art and leave the rest alone. Every page in the PDF has to be the same size.

The numbers

Your trim size does not change. What changes is the size of the pages inside the PDF.

Bleed adds 0.125 inches to the top, the bottom and the outside edge. Nothing is added to the inside edge, because that edge is bound into the spine and never gets trimmed.

So the height gains 0.125 twice, and the width gains it once:

• Height: trim height + 0.25 inches
• Width: trim width + 0.125 inches

For the usual large coloring book at 8.5 by 11 inches, the PDF pages are 8.625 by 11.25 inches. The book that arrives is still 8.5 by 11. The extra is what the blade removes.

The margin that catches people

The inside margin is bigger than the outside one, and it is the number most first-time publishers get wrong.

That inside margin is the gutter, the part of the page that curves into the binding. Artwork that sits too close to it disappears into the fold, and a child coloring near the spine ends up pressing the book flat to reach it.

For a book of 24 to 150 pages, which is where almost every coloring book lands:

• Inside margin: 0.375 inches minimum
• Outside margins: 0.25 inches minimum without bleed, 0.375 inches with bleed

The inside margin grows as the book gets thicker, because a thicker spine swallows more of the page. At 151 to 300 pages it is 0.5 inches, and it keeps climbing from there. You will not be near that with a coloring book.

Treat these as floors, not targets. A little more room than the minimum costs you nothing and makes the page easier to color on.

What the file has to be

Six things, and they are all checkable before you upload.

• PDF, which is required as soon as you use bleed
• All pages the same size, matching your chosen trim, with or without the bleed allowance
• Fonts embedded
• Images at 300 DPI minimum, and Amazon suggests staying at or under 600 to keep the file manageable
• Transparency and layers flattened
• No crop marks, trim marks, comments, annotations or placeholder text

Keep the whole file under 650MB. A coloring book of line art will not come close.

If a tool made your pages

Check the page size before you assume it is right.

I make the pages for my books with ColorCodex, which sits inside ColorBot Studio. It is $27 once, with no monthly fee on the tool. I am an affiliate with this product. I may receive a commission with your purchase at no additional cost to you. It runs on top of ChatGPT and needs a paid ChatGPT membership, Plus or Pro, which is a separate cost.

The thing worth knowing is that a generated file can come back at the wrong dimensions, and the fix is to say so and get it corrected rather than to start over. That is true of any tool. Open the PDF, check the page size against the two numbers above, and if it is off, have it redone at the right size before you upload anything.

Questions people ask about this

Do I have to use bleed?

No. Bleed is optional for the interior. It is only required if your artwork runs to the edge of the page. Covers are different: a cover always bleeds. Here is how to make a KDP cover for your coloring book.

Can some pages bleed and others not?

No. Every page in the PDF has to be the same size, so if one page needs bleed, the whole file is built with bleed.

What size should my PDF pages be for an 8.5 by 11 coloring book?

8.5 by 11 inches with no bleed. 8.625 by 11.25 inches with bleed. The printed book is 8.5 by 11 either way.

Why is the inside margin bigger than the outside one?

Because the inside edge goes into the binding. Part of that margin is lost to the curve of the page, so you start further in to end up with the same visible space.

Can I upload a Word document instead?

For a book with no bleed, yes. KDP accepts several formats. The moment you use bleed, it has to be a PDF, and for a coloring book of full-page images a PDF is the sensible choice anyway.

The file setup is one step. If you want the rest of it in order, I wrote up what I learned into The Coloring Book Business Guide, which covers finding a niche that is not already flooded, the tools for generating pages, the pricing decision, and fifty prompts to start from. Twenty-five for adult books, twenty-five for children's. It is free.