whips out indie comic "Teahouse" to see where it's printed
So it says on the back by the ISBN "Printed in Canada" and inside on the copyright page it says "Printed by Transcontinential". A quick googling got me this
https://tctranscontinental.com/printing
I'm too lazy to dig through for their ToS on NSFW hard smut policy, but judging by how open the comic was, it's likely pretty okay. I will say, the Teahouse comic has little more than the online version in that "steam" now doesn't block a visual penis, and there's a few more pages here and there across their chapters that show sex scenes, but there is never ever a clear depiction of the head of a penis on the page. Either the comic artists didn't want to draw "that kind" of comic, or the printers ToS does not support open eroticism.
An example of the Teahouse comic's page that's released online - http://www.teahousecomic.com/comic/?id=42 (depicts two men having sex, anime style, although everything is censored in that you cannot see anything, but it is more than clear what is happening).
For those curious, Japanese artists have similar issues with their creations and their publishers in that sometimes stuff they want to be either A) more sexual or B) more violent are not supported by their publishes and they turn to doujinshi (what we refer to as fancomics or indie comics) under an alias.