How to make invisible ink

Amazing formula for making invisible ink? With could only be seen under UV/Black light? How to make invisible ink?

1. Take out the tube of ink that inside the highlighter, and pull the tip (the part you write with) out of it with pliers.

2. Put the tube and tip into a cup of water. Put it in the microwave until it starts boiling.

3. Take out the tube with the pliers and squeeze all of the ink out into the cup. Do the same thing with the tip.

4. Add enough water so that you can see through the water clearly but it is still dark. Put the tube and tip back into the cup and put it in the microwave until it boils again.

5. Put the parts back into the highlighter. Dip the pen into the ink and write with it! To save the ink put it in a water tight jar so you can refill your pen. Your ink will show up under a UV light or black light or infrared light glasses.

There is other way to get invisible ink, more professional than the one you made by yourself. You can buy invisible ink from marked cards manufacturer. Their invisible ink can mark on playing cards, domino and white paper.