Agreed, I’d love it available as a shirt mog.
Apparently one can use the Inkbinder’s Spike object in Stormheim to apply the Runescribed Tattoos buff, which will give you the appearance of the tattoos for an hour while outside in the Broken Isles.
So it is available, but only obnoxiously restrictively and temporarily, and not as a mog. ![]()
The Inkbinder’s Spike apparently shares the same spawn point as the NPC Kottr Vondyr, at least according to a comment on wowhead. Here’s Kottr Vondyr for reference: