Blacklight reactive ink is a great way to have a tattoo that no one can see but under the blacklight. So you could, in theory, cover your entire body in tattoos and until you go clubbing, nobody would know! I think that's pretty cool. I'm thinking of having "I hate you" tattooed on my forehead.

A stealth tattoo that's almost invisible... until the UV light turns on.

If I ever get a tattoo this is the dye I'm using- I'm already imagining the fun I can have showing it off in the nursing home. Adapted from an FDA approved ink that was developed to mark and track fish this dye has been used safely for over 10 years.