Starting June 14, Smashwords updated their requirements for covers to get into their Premium Catalog (worldwide distribution through Apple, etc.). They are planning ahead for requirement changes in August from Apple: Apple will start requiring that the covers be at least 1400 pixels on a side. The minimum requirements for Smashwords still are 600 pixels on the short side, but that will not get you into the Premium Catalog, and you want that.
Previously, I’d recommended covers be 750 by ~1000 pixels. It ended up being 750 by 1150 pixels to be proportionate to a 6 by 9 cover, or 750 by 1200 for a 5 by 8 cover (the two most popular print sizes).* However, with the requirement changes in August, that won’t work.
Here are what the requirements will be:
- Smashwords: 1400 pixels shortest side minimum.
- Kindle Direct Publishing (Amazon): 1000 pixels minimum longest side, recommended 2500 pixes longest side.
- PubIt (B&N): 2000 pixels length maximum, longest side.
The minimum size of a Smashwords cover will be 2100 pixels (proportional to a 6 by 9 cover) or 2240 pixels (proportional to a 5 by 8 cover), which is incompatible with PubIt requirements.
So here are your options if you want to use all three sites (and why not?):
- Resize your cover to 1400 by 2000 pixels, no matter what the original dimensions are, and risk it looking weird as the proportions change, then use it at all three sites (not recommended).
- Go with two different covers until B&N changes their requirements to look equally pretty as Apple.
Keep in mind that existing covers will be grandfathered in, according to Smashwords, so you won’t have to resize existing covers unless you update the cover for some other reason.
I recommend switching to two covers:
- Smashwords/KDP covers at 1500 pixels on the shortest side. This will lead to 1500 by 2250 for 6 by 9 proportional covers and 1500 by 2400 pixels for 5 by 8 proportional covers (with the benefit of being able to just set the short side at 1500 and let the program work the math, knowing you’re safe).
- PubIt covers at 2000 pixels on the longest side (or 1250 pixels on the shortest side, whichever is easier to remember).
- These covers are probably bigger than you want for a website small picture for promotions. I’d go with 750 pixels on the short size for blog posts and 200 pixels on the short side for sidebar stuff.
I also recommend that if you’ve been buying 72 dpi images that you switch up to the next resolution bigger. I use Dreamstime; the largest size of the 72 dpi pictures goes up to 533 by 800 pixels, which is WAY smaller than 1400 pixels on the short side and will probably look bad at the new sizes.
Something I think everyone should take away here: save the master file in a higher resolution (300 dpi, probably), and resize to the smaller dimensions using a different file, because who knows when the standards will change again…
*A 6 by 9 cover is a 1.5 ratio and approximates a trade paperback size; a 5 by 8 cover is a 1.6 ratio and approximates a mass market paperback size. (The Golden Ratio is 1.61803399-ish, if you follow such things.) Personally, I recommend going with a cover size that wouldn’t be incompatible with the print book, because it’s a pain to resize those things anyway, and you want to do less resizing rather than more. KDP recommends going with the 1.6 ratio.