9 | Images

Two scenarios, here:

  1. Your projectx already has images in the file
  2. You plan (or want) to add images to projectx as soon as you figure out how to do it

This section tackles image handling.

First -- right up front so there's no confusion -- any existing images in projectx must be removed and replaced by production slugs.

Here's why: Images and all their coding are lost during the conversion to HTML. I know that sounds like all-six-chambers-full-of-suck, but this is actually a good thing. Sigil makes image-embedding simple. Even better, the way Sigil handles the coding ensures images can render properly on devices and apps (or at least those devices and apps that support images).

It should go without saying (but I'm gonna say it anyway) that if you plan to put images into projectx, now is not the time. At this stage in pre-production, we're dealing strictly with decision-making, organization and marking where the images will go with production slugs.

Bottom line, DO NOT ADD IMAGES TO THE FILE yet. Any existing images must be removed and replaced with production slugs, or you will have a confusing, labor-intensive mess on your hands later.


I really hate to add this statement to the tutorial, but I think this needs to be said. Images in ebooks ARE A PROBLEM. Many, many things can go wrong, a lot of which is completely out of the producer's hands, like the type of device an end-user might use, differences between different display platforms, and bugs in platform coding. Unless images are absolutely necessary to tell a story, please leave them out. They're unreliable, and can be expensive to the author in delivery costs should the total file size exceed 3MB.

I am not saying images are not possible in ebooks. I am saying that rendering problems can and will frustrate new producers to the point of tears. So unless you've got a solid foundation in HTML, CSS and the current limits of EPUB/MOBI development, you're much better off keeping images to a bare minimum.

Now for an entire page worth of image-specific rules, cautions and tips...

Section Index


The first (and only) hard rule of images is that they simply cannot appear in-line with text. Images must be centered on their own line.

Come To e-Jesus Image List:

  • Inline images: Readers can adjust font size and line-height. Those adjustments apply only to text, but not to images. Imagine thee resultant visual vomit for a moment, then place the image centered on its own line, where it belongs.
  • Inline images: Unless custom, risky CSS that is not supported on many e-reader devices and apps is applied to an image, words will not wrap neatly around an image. Rather, words will cut off, and the graphic will render God-knows-where in your paragraph, kicking your reader off the page. #gameover
  • Images general: I can’t believe I have to add this note in this day and age, but do not use images without the proper licensing. When in doubt, leave it out.
  • Images general: 72dpi is recommended for EPUB/MOBI. The resolution is more than sufficient, and higher resolutions drastically increase file size with no added benefit.
  • Images general: Every image must appear on its own line.
  • Images general: Images must always be styled align center. (This is tackled in Sigil.)
  • Images general: Recommended max width of images = 500px.
  • Images general: Be mindful of colored images. Make sure they render well in grayscale because many e-reader devices render only black and white.

A Note About Amazon

Images can drastically increase the file size of finished EPUB and MOBI files. Files larger than a certain size may prohibit authors from setting their price the way they’d like, or receiving the 70% royalty rate.

At the 70% royalty rate, Amazon has a scale of delivery costs found here:


(Scroll down to D. Delivery costs.)

Also, if you run a sale on Amazon, always double and triple check your royalty rate afterward. Any sale price less than 2.99USD, and Amazon will automatically bump the royalty rate down to 35%. Amazon will not reset the royalty rate to 70% later when the sale is over and the file returns to regular price.

Basically, unless it’s absolutely necessary, minimize images in files (or at least make sure to use the smallest files possible). Sometimes they’re more expensive than authors realize.

Image Slugs

If there are images currently embedded in projectx, they need to come out and be replaced with a production slug.

If you intend to put images into projectx later on, a production slug needs to be placed into projectx to mark where the images should go.

Images embedded in word processor files -- and all the latent buggy code that comes along with them -- does not survive the trip into raw HTML land.

  • Delete the images from projectx.
  • Mark each one's spot with a production slug.

My image placeholders usually look like ##imgname##. That way, I can use Find to navigate right to the slug.

Example One

Each unique image should have its own unique slug. For instance, if you have three different images, use something like ##img1##, ##img2##, ##img3##.



Example Two

Conversely, repeated images should share the same slug. For instance, if img1 appears in three different places within the same e-book, the ##img1## text slug should be used in each of those three places.



Rename your image files accordingly, and make sure they land in the desktop production folder.

Keep very careful track of slug and image file names. For any project with more than three images, I keep a spreadsheet with columns for slug name, image name, and the directory location where the image is stored on my computer.

Later, in Sigil, we’ll use Find to locate all these slugs, and then replace those slugs with the actual images once more. Sigil makes this ridiculously simple, and ensures the image files are properly embedded.

ACTION list: Image Handling

  1. Replace all images in the prep_projectx file with expediently named production slugs.
  2. Ensure every image appears on its own line. Images must never be embedded in-line with text.
  3. If necessary, rename image files to match production slugs. This will make life much easier in the production stage.
  4. Ensure all images used in projectx are saved in the desktop production folder.
  5. Note the position of image production slugs in the key_projectx file.


Plain-old save the prep_projectx file to preserve all changes. (No need to rename this version yet.)

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Subpages (1): 9.1 | Images Checklist