Does KDP print quality vary across books printed at the same facility?
(Discussion of this post on Reddit’s r/selfpublish)
This week, I finished reading Theft of Fire by Devon Eriksen. It’s a lively and fun story set in an Expanse-like future, but this isn’t a book review :) Rather, I’m asking a question about Amazon print-on-demand: what’s up with the variation in print quality between Kindle Direct Publishing books printed at the same facility, within just a few months of each other?
I had been hunting around in r/selfpublish for a new indie sci-fi author to check out, and the intro pages of Theft hooked me and made me want to read more. So I ordered it on Amazon, and it showed up a few days later. So far, so good!
I typically read books while lying in bed, with the book propped up just a couple of feet in front of my face, right under a reading lamp. And as I read Theft, I noticed that if I looked really closely, the text was slightly fuzzy. At normal arm’s length, it looks perfectly fine and legible, but close up under a lamp, the font edges were a bit rough.
I pulled a copy of my own indie sci-fi book, which had been printed at the same KDP facility in Coppell, TX as Theft. Comparing a single word in a 1200 DPI scan, here’s mine on the left, and Theft on the right:
I had previously seen that KDP black-and-white interiors seemed to be laser-printed, but Theft seems to be inkjet printed, more like what IngramSpark does. Here’s a look at the print-on-demand information from the last pages of both books, again with Theft on the right:
So what’s going on here?
I’ve come up with a few possible answers so far:
Perhaps KDP uses a different printer for different paper types? But no, both books use the same options: black ink and 50-61 pound cream paper. I compared a 100-page stack of pages from each book, and they were identical thickness and color, as far as I could tell.
Maybe if a book contains black-and-white chapter start images, KDP routes it to an inkjet printer to avoid halftoning artifacts? But my book also has chapter start images, though they’re smaller than those in Theft, so that doesn’t seem likely.
It could be that if a book’s PDF source includes images in a non-grayscale color space like DeviceCMYK/DeviceRGB instead of DeviceN, or text which uses a color other than 0C 0M 0Y 100K, KDP might route the book to the inkjet printing flow used for standard color interiors, which are inkjet printed. I can’t check this without access to the PDF source, though.
The most annoying possibility: KDP has both laser and inkjet printers, and books go randomly to one or the other, so the customer has no idea what they’ll get.