One of the most frequent questions I get asked is, “What size should I tell my illustrator to make my children’s book artwork?” The answer depends a little bit on the size and layout of your book (and whether you plan to do a print version), but in this post I’ll provide guidelines and answers that should work 99% of the time.
Even though most people want to know about sizing, there are several other important image specifications you should pass along to your illustrator (or take into account yourself if you’re doing your own illustrations).
First, The Short Version
If you hate reading and just want to cut to the chase:
Your images should be at least 2500 pixels per side (preferably larger), at 300 pixels per inch resolution, in RGB color format, delivered in .jpg format. Read on for the reasons why and a bit more detail.
In general, you should have your illustrator send you .jpg files, since these are easy to insert into your Word document or other word processing file. It may be possible to use less-common file types like .tiff files, but I haven’t used these myself and can’t vouch for them. I recommend having them also send you the original “raw” artwork files like Photoshop (.psd) or Illustrator (.eps or .ai) files, but you won’t want to actually insert these into your book file.
This was a weird lesson I learned with one of my earliest books- be sure to have your illustrator use RGB color mode, instead of CMYK. For some reason CMYK images come out looking very dark on Apple devices like the iPad or Macs, so go with RGB colors to be safe.
Make sure your illustrator creates computer-generated images (or scans in hand-created art) at 300 pixels per inch, rather than the 72 ppi that is OK for most graphic design and web images.
This is because you’ll need the artwork to be 300 ppi to be able to get it printed, and it’s much easier to get it done at the right quality the first time than to have the illustrator try to go back and fix it later. This resolution also just looks really crisp and nice on high resolution screens like Apple’s “retina” devices such as the new iPhones and iPads, and I assume on the new Kindle Fire HD devices as well.
At the end of the day, there’s really no reason for illustrators not to use 300 ppi, so you might as well.
Finally, everybody’s biggest question. The reason I saved it until last is that the dimensions depend on whether or not you use 300 ppi as I suggested above.
Assuming you do, I recommend having your illustrator make the images quite large- at least 2500 or 3000 pixels per side, if not bigger. When you insert them into a word processing document they’ll automatically be sized down to fit the page with no loss of quality, but you want them to be very large to begin with because you can’t go back and make them larger after the fact without them looking grainy and ugly.
The large size is especially important when doing print books- my print books have all been 8.5″ square, and the images don’t “bleed” all the way to the edge of the page, so the 2500-3000 pixel size has worked fine for me. However, if you’re planning on doing larger pages than that, or having images bleed all the way to the edge of the page, you may want to go even larger so they don’t get stretched or end up too small.
If you’re only planning on working with Kindle or other digital publishing, the 2500 pixel size should be as big as you should ever need.
That’s it! By following those guidelines you should end up with images that look great and work well in your book for both digital and print versions. I hope this article was helpful!