In this blog post, I want to talk about image preparation for your book. You may not know it, but there are requirements for the images that you add to your books. If your images don’t meet the guidelines where you intend to publish then your book will be rejected. If your book is mainly for print, your images need to be at least 300 dpi resolution in CMYK color format. You ebook images can be in RGB color format but they should still be in 300 dpi resolution.
300 dpi resolution is what higher quality resolution images usually are. Some high-quality images have a higher resolution than that. But the key words here are “high-quality.” If you using high-quality stock photography or images that you have taken with an expensive camera, that is great. But, say you are writing a book on your family’s history or a book about history in general. If that is the case, then there is a good chance that your images will be old, poor quality ones. If your images are old, low resolution such as 72 or 96 dpi, they can be brought up to 300 dpi easily in Photoshop. The color format can even be changed to CMYK. But the problem is that it won’t improve the quality of them. In fact, it will make it worse. Raising the dpi up to 300 makes them larger which creates a blurry low-quality image.
The truth is that if you have low resolution, poor quality images there is no creating high-quality images out of them. It can’t be done. For an image to be high quality it has to start out that way. You can add quality to an image that is poor quality to begin with. I run into this all the time when I am formatting books for people. There are times when people send me the worst images for their print books and I have to tell them that the quality can’t be improved and they won’t look good no matter what is done. Which is why I state right out on all of my gigs that I don’t edit images for quality. And the reason why is that it can’t be done. This is why it is important to read the guidelines for the site that you intend to publish on. This way you will know what to expect before you start. If you are adding images to your book then you will know what type you need to add.
Now, as far as the requirements for print books for the self-publishing sites go, they state that images need to be high quality 300 dpi images in CMYK color. As I already mentioned, all images can be brought up to 300 dpi in Photoshop and the color format can even be changed. But the quality could still be poor. With some self-publishing sites, this could be a problem because some companies are pickier than others. I have found with my customers that Amazon KDP is not as fussy. They will let those images through as long as they are 300 dpi. But if you publish on a site like IngramSpark, your print book could get rejected because of poor quality images even if they are 300 dpi in CMYK color. This company is very picky about everything. So if your book is rejected for that reason, the only way to fix the problem is to choose better quality images. The site, or sites, that rejects your book, for this reason, won’t let you publish until you do.
CMYK color refers to the four inks used for color printing, which are cyan, magenta, yellow and black. To change this in Photoshop, go the menu at the top where it says Image > Mode. There you will see all of the different options for your images. CMYK and RGB are on the list.
The downside to this color format is that the colors can be duller and not as vibrant as what is used for ebooks and the web which is RGB color format. RGB stands for red, green, and blue. I won’t go into a full explanation of color formats here. That could take an entire book to explain and there are many good ones out there on color theory if you are interested. If you take the same image side by side and compare it in CMYK color format and in RGB color format, you will see that in CMYK the reds are bit duller, the blues aren’t as vibrant, on and on, etc. Which is a shame I know, but it is the image requirements for print books.
For ebooks, it is a bit different. As I said in the first paragraph, you can use the RGB color format but your images still should be 300 dpi in resolution. Your images can be in either RGB or CMYK color format for an ebook. It doesn’t matter, both will be accepted. Which is not the case for print. Print has to be CMYK color format. If you are publishing your book in both ebook and print book formats then you could just make your images 300 dpi resolution in CMYK color and that way you won’t have to two separate images that you have to add to your files. It is completely up to you.
But if your images are below 300 dpi, upping the dpi isn’t going to help the quality issue if your images are low quality to begin with. You will still have the same problem for the ebook as well. So when you are adding images to your book you need to consider the ones you choose carefully. The guidelines for the self-publishing sites have to be followed. That means if your images aren’t at 300 dpi in CMYK color for your print book then they will have to be changed to that. If you don’t know how to do that and are having someone format your book they will probably do that for you. I do that as part of my formatting gigs. But remember, bring the images up to 300 dpi from a lower dpi will probably degrade the quality of them. And there is nothing that your formatter or even you can do about that. If you want high-quality images results, then you need to choose images that start out that way.