Combine the back cover, spine area, front cover, bleed, safe areas, and barcode space using the current KDP template.
You will leave with one cover PDF made for the final trim, paper, and page count.
Build file 2
Make the full paperback cover — not just the front image.
Every KDP paperback cover needs bleed. A custom cover is one file laid out as back cover + spine + front cover, with a protected barcode area.
Back coverBarcode area
Spine
Front cover
0.125 in bleed
Keep text inside safe areas
Most short picture books should have no spine text: a custom KDP cover needs at least 79 pages for spine text, while Cover Creator requires at least 80 pages.
Recommended
Use Canva with KDP's cover template
Finish the interior first, then enter its binding, ink, paper, trim size, and final page count in KDP's Cover Calculator.
Download the PNG template. In Canva, create a custom-size design that exactly matches the full template dimensions and upload the template as a locked guide layer.
Place the ReadKidz front-cover art on the right panel, design the back on the left, extend backgrounds through the bleed, and keep the barcode and safe zones clear.
Delete or hide the KDP template layer. Download one PDF Print file with Crop marks and bleed turned off — the template dimensions already include KDP's required bleed.
Upload the PDF in KDP and inspect the front, back, spine, barcode space, and every outside edge in Print Previewer.
Do not keep clicking through the same warning. Correct the Canva document, source image, or cover template that caused it, export a new PDF, and run Print Previewer again.
What KDP shows
Likely cause
Direct fix
The cover size or spine does not match
The cover template was generated before the final page count, paper, ink, binding, or trim settings were locked.
Finish the interior, generate a fresh KDP cover template, rebuild the Canva cover at that exact full size, hide the template layer, and upload a new cover PDF.
Not currently. A print cover can require the back cover, spine, front cover, bleed, and barcode space in one file. Use KDP Cover Creator or build a separate cover from KDP's template for your selected trim size, paper, and page count.
Can I prepare both KDP files in Canva?
Yes. Use a custom-size Canva document for the interior and a separate Canva document that matches KDP's exact full-cover template. Download both as PDF Print with Crop marks and bleed turned off when your document dimensions already include the required KDP bleed. Canva does not fix a low-resolution source, so check the PNG pixels first.