recipe of temporary tattoo ink

You could use Henna. Or you could use tempera paint and cold cream...What are you going to use it for? I use to make my own clown make-up and I have worked with children. I could help you more if I knew the context you were going to use it. Also Stampin UP! sells a tattoo kit, you stamp on the image with their non-toxic ink then color it in with their non-toxic markers.