Sizing and Manipulating Images for Pressbooks
By Elizabeth Mays |
We get a lot of questions about importing images into Pressbooks. We thought we’d answer those here.
How to Size Your Images for Ebook Production
Before you upload your images into Pressbooks, you’ll want to make them as small as possible while still retaining quality. Why? Bookstores charge you a delivery fee based on the size of your book in megabytes, and images make your book larger. Kindle, for example, charges you 15 cents per megabyte for every sale you make. And, our ebook plan is limited to 5 MB of storage. You could easily exceed that with just a few photos if you don’t resize them before uploading.
If you’re doing an ebook only, you can make your images smaller than you could if you’re doing both ebook and print. For ebooks, we suggest not making images larger than 250 KB. In terms of dimensions, 1:1.5 is a safe ratio.
There are many tools you can use to resize your images outside of Pressbooks. Many people use Photoshop. But if you don’t have that, there are plenty of free and low-cost apps out there that will let you resize and edit your photos online, from your desktop or on mobile. One such tool is Pixlr, which has both free and low-cost apps you can use.
Updated! Sizing Your Images for Ebook and Print
In Pressbooks, you’ll upload the same images just once for ebook and print. If you’re going to do both an ebook and a print book, we recommend keeping the images you upload around 1-2 MB per file (files cannot be over 2 MB to upload into Pressbooks) and 300 dpi. Our experience is that images of that size render fine in print. Make sure you select “full-size” in the image editor, otherwise a smaller/compressed version of the image will be exported.
To make sure you’re not charged for larger photos in your ebook, check the option under Appearance / Theme Options / Ebook Options to compress your images in the ebook export.
How to Upload Images in Pressbooks
We have a chapter in our User Guide on how to upload images into the Pressbooks interface. You can also check out our video tutorial on the subject.
How to Edit Images in Pressbooks
If you don’t have image editing software, you can edit images from within Pressbooks. This User Guide chapter will show you how.
Photo Books, Children’s Books and Illustrated Books
Pressbooks does handle images, but it’s not necessarily the best tool to do image-only, or heavily designed books. It’s built for text with images … but not to make picture books.
That said, if you’re willing to do some custom coding and trial and error, you may be able to hack something. We suggest you play around and see if you get what you like.