How can you tell when you've run out of invisible ink?

lol

Best type of ink to get, because you never run out of it. It just goes on and on and on etc....... And by the way no refills are ever requried and it doesn't burn a hole in your pocket either. Great loved that one. Thanks. But I have noticed you didn't use it or have you??????? lol

Rofl, nicely while i replaced right into a boy i used lemon juice.. not sure what your employing yet an basic try might desire to artwork. attempt sticking your finger interior the ink nicely...if it disappears you nevertheless have some left :)

You never run out if it's invisible. lol

Your invisible brain cells will tell you.

the ink will become visible.

You've always been out!

Shine the light!

Lol...

Or you can ask the genie?

You can see it before it dries.

When s.h.i.t is not coming of the pen

easy. that's so easy i'm not gonna answer