How can i make invisible ink?

Ok there is this thing called invisible ink. You throw it on peoples clothes and they like freak out or something (because its like a stainable color like blue or something i dont know) and then instantly it dries and you can’t see it anymore. Its like it was never there. My friend had it once and it was so cool!! It’s like a magic trick but there is something in there or things combined to make it disappear. Please dont just write down a recipe because I do NOT like stained clothes at all thats what makes the invisible ink funny to me! So please can you give me a recipe. If you dont have one but want to help me please google it or something! Thanks so much!!