Book Cover Sizes and Specs

In my first essay on book covers, I described why it may be necessary to design your own, and how to follow Frank Frazetta’s concepts. In the second, I discussed how the transfer from digital to print results in a darker cover. It occurred to me that I never mentioned the physical aspects of book covers, whether you design your own or hire a professional artist.

Let’s change that, shall we?

If you hire a professional artist from Fiverr, or elsewhere, he or she ought to know all this already. If you’re the artist’s first customer, possibly not. If you design your own, it’s important, as I found out.

Whether we design a cover for a print book or an ebook, we work with digital images. In my case, those images are 3D art renders. If you take a photograph of a painting, a landscape, or people, it’s still a digital image. Even if you use film, and scan the image, the final product is digital. So, the theories are the same across the spectrum.

Digital images are variable in size. My renders are almost always either 1800 x 904 or 1500 x 904, measured in pixels. Depending on the usage, the site, and the device, they can appear to be small photos or full screen wallpapers.

Print doesn’t work that way. It’s fixed! The most common sizes are 6 x 9 and 8.5 x 11, measured in inches. There are other sizes, usually reserved for gift books, art albums, and cookbooks. Those lie outside the scope of my experience. That geehonking big 1800 x 904 render is puny on a 6 x 9 page, measuring about half the available space. That’s fine for the back cover, but not the front.

Therefore, the cover image needs to be at least twice the size of what is normal for a digital art image. The final render for my 6 x 9 cover measured 3600 x 1800. The 8.5 x 11 cover required a gigantic 4800 x 3600.

It is always better to shrink a digital image than to blow it up. Shrinking tightens the pixels, while blowing it up distorts the pixels. A blown up image is fuzzy at best, full of odd and ugly geometric shapes at worst. Hence, the term “pixilated.” That is another reason for using an image that borders on the insane size.

As if that isn’t enough, you will also need to add in trim area. This is the part of the image that spills over into the paper that will be cut off. Make sure the image extends to the very edge of the paper. In other words, for a 6 x 9 cover, you need 6.5 x 9.5. This ensures a nice image all the way to the edge of the book, without any black or white border showing up.

For a cover to an ebook, you have a different size dimension to consider. Covers for ebooks are much more square in shape. I’m trying to memorize the dimensions, but they’re closer to 610 x 950, measured in pixels. Too tall or too narrow, and you end up with wide margins at the sides. Worse, Lulu and Amazon may stretch the image to fit the space. That results in a terrible looking thumbnail. A customer seeing it may think the contents are equally terrible, and not buy your book. Trimming your image requires quite a bit of trial and error, but you’ll get it. Amazon and Lulu both give you the exact dimensions, so that is a major help. They differ, so if you publish both Kindle and Nook editions, you will need two separate covers.

Whether for print or ebook, the cover image must be set to a DPI of 300. I’m not sure how Photoshop operates, but GIMP defaults to 72 DPI. That is not nearly sharp enough for print. When an image is scaled in GIMP to 300 DPI, the program shrinks the image. Keep that in mind and scale both DPI and physical dimensions (width and height) at the same time. Lulu and Amazon both reject images that aren’t 300 DPI, so if yours isn’t, you’ll find out.

Also, remember to leave room for the title and author’s name. Text should not obscure the main part of the image. This image is marketing your book, and you want it to look as good as possible. Again, a professional knows this. If you design your own, keep textual requirements in mind.

Lulu and Amazon hate PNG files. Oh, they don’t tell you that, and accept them. At least, Lulu does. The problem with PNG files is that they contain transparent layers. These will be flattened in conversion. The result is a darkened cover. We’re already fighting dark covers as it is, so why make it worse? Use a JPEG file instead. Amazon wants only PDF files for covers, but even a PNG within a PDF will be flattened. Again, use a JPEG and save yourself a headache.

All right. Until next time, happy writing.


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