Formatting images for Kindle is a huge drag. The official KDP FAQs are laughably underdeveloped here, basically telling you that the four most common image types are supported (gee, thanks!) and not much else. Personally, I have completely redone the images in my textbook Game Theory 101: The Complete Textbook at least three times now, most recently because the way Kindle compresses images changed without any notice. I am writing this post to impart my knowledge on you.
Here are the most important time/money saving tips:
- This process is going to suck. You will think you are doing everything right, then the Kindle uploader will find a way to completely screw you over. An image will stop appearing. The image will appear blurry. Your document size will suddenly explode. You will become unbelievably frustrated at some point. Accept it now, and understand you will likely have to do some experimentation to fix these problems later.
- Kindles (and the .mobi file extension) were created to display text. Images were very clearly an afterthought. However pretty your image looks on your computer screen, it is not going to look nearly as pretty once you have uploaded it. Sorry.
- Do not use fine lines in your images. To compress file sizes, KDP evidently eliminates random lines of pixels from your images. If parts of your image contain lines that are only one or two pixels thick, those lines may magically disappear in the final version. In other words, make your images as blunt as possible. You can’t control which lines disappear, but that will not matter much if no single line is crucial to the image as a whole.
- By extension, if your image contains words, be careful which font you use. I originally used Cambria in many of my game theory payoff tables, but Cambria has a lot of numbers and letters with very thin lines. (The middle part of an e has this feature, for example. Without that middle line, you are looking at a c.) I switched over to Franklin Gothic Demi. It is blocky and ugly in PDFs. But Kindle is not PDF world. Blocky texts look great in Kindle world. You can also consider bolding other fonts to manually create blockier text.
- Do not create images larger than what you are using for your final product. In the normal publishing world, you should blow up all of your images, save them as large files, and shrink the dimensions once you have put them in the file. This ensures that the dpi (dots per inch) of the images remains large, which is important for printing purposes. But Kindle world is not the normal world. Following normal advice leads to two problems. (1) Kindle will randomly decide to remove lines of pixels, creating the problem described above. (2) Kindle will retain the larger file size, thus increasing the size of the document without changing the quality of the image on the screen. This means you will be unnecessarily paying greater delivery costs.
- You should also compress your images. To do this, I use IrfanView, which is the greatest image cropping software ever created. Simply paste the image into IrfanView and press “s” to save. When you choose to save as a JPEG, it will give you a range of quality options from 0 to 100. I suggest selecting 50 here, which is in line with KDP file size control guidelines. If you choose a smaller amount, the colors of the image will start to bleed into one another. Anything more hardly changes the observable quality of the image in the Kindle but sucks up file space. (And we want to shrink this to save on delivery costs.)
- Finally, some basic infromation: If you are writing your book on Word, you need to use the INSERT -> PICTURE command. If you copy/paste an image directly into the document, the image has a nasty tendency of disappearing when you upload the book. If you have a lot of images in your book, I suggest adding this to Word’s quick access toolbar.
Following these guidelines has decreased Game Theory 101‘s delivery costs by $0.03. While that might not seem like much, if you sell eight copies a day, that’s almost $90 over the course of the year. It has also increased the attractiveness of the book, which one would imagine correspondingly increases sales.
Let me know in the comments if you have any other tips, and I will be glad to add them here.