Paperback Cover Wrap: How to Build One for KDP

An ebook cover is just a front. A paperback cover wrap has to cover the whole object: a back that sells, a spine people can read on a shelf, and a front that matches the one readers saw online. The maths is simple. It still has to be exactly right, because KDP’s print files don’t forgive mistakes.

The figures below come from KDP’s help pages, which work in inches. They can change, so check the live pages and the cover calculator before you finalise anything.

How do you turn an ebook cover into a full wrap?

You start from the front cover, but you can’t simply blow it up. The ebook file is made for screens in RGB colour. It’s often a different shape from your trim size too. For print, you rebuild the front at the exact trim size with the background extended past the edge. Then you design the spine and back around it.

1. Choose your trim size, such as 5 x 8 inches, and your paper type.
2. Finish the interior so the page count is final.
3. Work out the spine width and the total cover size.
4. Rebuild the front at trim size, with bleed.
5. Design the spine and back cover, then export to PDF.

Working on a series? Build every wrap from the same template so the spines line up on a shelf. Our book cover design for authors service handles ebook, paperback, hardback and audiobook formats together.

How do you calculate spine width from page count and paper type?

Spine width is your page count multiplied by a factor that depends on the ink and paper. KDP’s paperback cover guidance gives these figures:

Here’s a worked example. A 300-page novel on cream paper has a spine of 300 x 0.0025, which is 0.75 inches. Print the same book on white paper and it comes to about 0.676 inches. The full cover width is the back cover plus the spine plus the front cover, with bleed added at both ends. The height is bleed plus trim height plus bleed. So a 5 x 8 inch book with a 0.75 inch spine needs a cover 11 inches wide by 8.25 inches high.

KDP also has a cover calculator and template generator. Enter your ink and paper choices along with the trim size and page count, and it produces a layout that marks out the bleed and the safe areas as well as the spine. Use it. If your page count changes after final formatting, recalculate, because a wrong spine pushes text over the fold onto the wrong side.

How much bleed does a paperback cover need?

KDP’s page on trim size, bleed and margins says a cover needs 0.125 inches (3.2 mm) of bleed. Backgrounds and images have to run right to the edge of that area, so a tiny shift during trimming won’t leave a white sliver.

Keep anything you can’t afford to lose well inside. KDP says content you don’t want trimmed should sit at least 0.25 inches (6.4 mm) from the outside edge. Its cover guidance also wants text kept at least 0.125 inches inside the trim lines and out of the spine area. A little variation in printing is normal, so leave the design some breathing room, especially on a busy spine.

What goes on the spine?

Most readers see a paperback spine on a shelf or in a pile. The title and author name need to be readable at a glance. Add the series name or number if there is one, plus a small publisher mark if you have it.

Two limits apply. First, spine text is only for longer books. KDP’s guidance says you need at least 79 pages, while Cover Creator asks for 80, and one line on its page says “more than 79”. To be safe, treat 80 as the minimum. Second, spine text needs at least 0.0625 inches (1.6 mm) of clear space on each side so it doesn’t wrap round onto the front or back. KDP also counts a small spine shift either way as acceptable print variance. Avoid any design that depends on the spine edge lining up perfectly, such as a hard-edged block of colour.

Where does the barcode go?

You don’t have to supply one. KDP says you can upload a cover with or without a barcode, and if you don’t add your own, it puts one on the back cover automatically. The template marks out a barcode area, which keeps the code from shifting in print and helps it scan.

Plan the back cover around that space from day one, since it shapes the layout of the blurb. Keep text and key artwork out of the barcode area, and make sure the background is plain where the code will go.

What should the back cover say?

Treat the back cover as a sales page in miniature. The usual order runs from a hook line to the blurb, then one or two short review quotes or endorsements, and finally your author line or website. Keep the blurb shorter than your Amazon description, because it has to fit around the barcode and inside the margins.

• Hook: one line naming the tension or the promise.
• Blurb: short paragraphs that make the stakes clear, with no spoilers.
• Quotes: real ones only, correctly attributed and used with permission.
• Series information: the list of titles, if the series is a selling point.

Choose readable type. KDP’s guidance sets a minimum of 7 point, but back-cover body copy looks better at a comfortably larger size. Always order a printed proof. Small type and dark backgrounds look different on paper than they do on screen.

What file does KDP want for a paperback cover?

KDP’s page asks for one PDF with the whole wrap as a single image, ideally no bigger than 40MB. The artwork should be CMYK and flattened to one layer, at 300 DPI or higher. Embed the fonts, and take out any crop marks or colour bars. Spot colours aren’t allowed, so convert them to CMYK. Check your colours in CMYK before you sign off the design, because bright screen blues and greens often print flatter than you’d expect.

How we can help

We started out as the in-house team for our founder, USA Today bestselling author Jack Cartwright, whose 60+ titles have all needed print covers. As part of our paperback and ebook cover design, we can take your ebook cover and build a print-ready wrap from it. We check the spine and back cover layout against KDP’s specifications, along with the file set-up. To see what else we do for writers, read about how we market self-published authors. We agree a clear brief, scope and fee with you before any work begins.

Sources

• Amazon KDP: Paperback cover creation and specifications
• Amazon KDP: Trim size, bleed and margins