At first glance, I'd assume it was a chop like I explained and showed (odd how similar the subject matter is) in the block print I made in college which you linked back to.
I'm about 95% sure it's still a signature chop, designed with a pictographic flare. The only thing that makes me hesitate is the clarity of shape and color on top (?) of the purple. My chop came from a fever dream Hong Kong tourist trap. I'm sure this guy has a far higher quality red ink than I do - because the alternative is that the red mark is a part of the carved block and was run as a third color pass in the print process.
While not impossible to get a perfect registration like that, it's the equivalent of splitting your first arrow with your second shot.
The red ink is an oily, stiff paste, denser than lipstick and fairly opaque, so it's more likely that he has better media than I do and that the opacity of the red totally covered the purple (without a trace of feathering or greasy halo...? Showoff.)
@ddtburg First, let me congratulate you on the prints. I'd be happy to give them a home if you decide to downsize. 😊
As for the moniker "Island," the reasons could include a geographic identity, a Shinto/Buddhist teaching that resonates with the artist, a childhood nickname, or a personal "tag" as you see with graffiti artists.
I think you'll have a hard time finding their identity, so it's a good thing the art is intrinsically wonderful and stands on its own merits even without a name attached.
