I’ve thought about making rubber stamps to take to the comics conventions- for a buck, you could get a quick rubber-stamp tattoo of whatever I had a stamp made for. Like, in this case, a bicycle. Maybe a lightning bolt. Pinup girl, ‘skateboarding is not a crime’ logo, Hufflepuff House icon, the usual.
Of course, when I was thinking of the idea, I was just thinking of stamping people’s biceps or the backs of their hands… maybe a forehead now and again. I think genitalia would cost a LOT extra, plus there’s the cleanup costs… soap, water, bleach, anti-bacterial goop, autoclave double-boiling… I dunno. Maybe just toss the stamps after.