Originally posted by Nuathala you drop the bottle with ink (eh..or without if it's empty) on the floor 'by accident' then you know for sure that it is empty so you can get a new one.
But that's a waste of ink!
Do you know how expensive invisible ink is?!?
It is very hard to get, you know. Almost everybody spills their ink. I'm not sure of it, but I heared from somebody, who had heared it from a friend, who had heared it from the brother of the wife of the distributer of invisible ink that most people, when they are in doubt wether they have some invisible ink left, 'accidentaly' knock their bottle with ink on the floor, so they are sure they haven't any ink anymore. 😉
Originally posted by TheMaster37 What does it matter that you're out of invisible inkt anyways? No-one is going to see the difference...
exept the one you are writing a secret letter to! 🙂
by the way, you could try to write a secret letter to yourself, and if you can make the ink visible some way, you know you weren't out of invisible ink (but you still don't know whether you are out of invisible ink now because you used some of it)