This is black light ink that I have tattooed in the negative space of my polynesian art. I used to be in clubs alot when I was younger but now, not so much. It is completely invisible until a black light hits it. Not very practical. Kind of a novelty tho. IF YOUR THINKING ABOUT GETTING A BLACKLIGHT INK TATTOO EMAIL ME! WE FINALLY GOT IT RIGHT ON THE THIRD TRY.