How do you tell when you're out of invisible ink?

Answer 1

Most 'invisible' inks are liquid, like India ink, for drawing with a pen nib. The fluid is visible while you are writing with them. Only when they dry are they not very noticeable. Then, when they are developed (by heat or chemicals) they change color and are easy to read.

10 NOV 06, 2057 hrs, GMT.

Answer 2

That's a good one. Better yet. How do you know that you actually have invisible ink? It's not like you can see if there's ink actually in the bottle right?

Answer 3

OK, that's a bad thing with invisible ink, but it can be worked out. Just put your finger in the ink bottle. If it feels wet, you still have some.
The good thing with invisible ink though is that it doesn't matter if you spill it on yourself or on the floor by accident; no one will notice...

Answer 4

Take a match and light the paper you wrote on. If the paper burns; you are out of invisible ink. If the paper does not burn; you still have ink.

Answer 5

It's only invisible when you endeavor to write with it, so you can tell you're out just like you can tell you're out with regular ink. Hope that clears things up, Special Ed or Edie.

Answer 6

You'll get an invisible pop up telling you to insert a new cartridge when the quality of the print is no longer acceptable.

Answer 7

I don't order it unless the company will send me one those "you're almost out of ink, time to reorder" forms.

Answer 8

Stick you finger in the bottle. If your pinky is missing the tip, you still have some

Answer 9

You notice that you can see what you're writing.

Answer 10

you sneezed 76 times and it'll refill every time.