When I wrote last month about the soothing properties of adult coloring books, I apparently missed something. As is the case with many other innocuous, popular products that for some reason needed to become gendered—pop, Kleenex, soap—there is a separate category of coloring books just for men.

Luckily, the BuzzFeed writer Grace Spelman tweeted about them, and I am no longer under the mistaken impression that whatever coloring book I might enjoy would be equally suitable for a man:

Amazon has a sizable sampling of these for sale, including some that are fairly NSFW. There’s the redundantly-titled Adult Coloring Book For Men: Realistic Coloring Book of Sexy Women and Hot Girls for Men. There’s also one that promises to take the colorer  “on a man’s journey”—which, from what I can glean, is creating, courting, and proposing to your dream woman, followed by lots and lots of sex, complete with genitals to fill in with your favorite flesh-toned crayon. There does not seem to be an equivalent of this coloring book for women (though there is the Mom Coloring Book, and one where you can color in the paintings of great women artists, which, frankly, looks awesome.)

We’ve also got The Manly Man’s Coloring Book, which includes cars, kegs, and an image of a flask with two axes and fire on it. And The Amazing Colouring Book for MEN (A Really RELAXING Colouring Book), featuring patterns of typically masculine-coded things like tools and sports equipment, as well as … means of transportation? And cameras? Which I never thought of as particularly gendered, unless I was trying to memorize which French nouns use “le” and which use “la.”

But while all of these are ridiculous, none are quite as confusing as that first one Spelman tweeted, which is, I swear to you, just patterns. Here are a few of its pages, courtesy of Amazon’s “Look Inside” feature:

Amazon.com

They’re not even patterns of stereotypically male things! They’re just lines and curves! Even when I try to make my brain as sexist as possible, I cannot fathom it. That one on the right is kind of spiky, I guess? And spiky things are phallic? I don’t know. Is there something that makes these patterns fundamentally different from these ones that are “for women?”  Or these ostensibly gender-neutral ones? If any pattern-ologists want to delve into this, I’m sure the coloring-book industry would thank you.