I did this by accident when I was younger. I was playing with my blacklight and some highlighters (writing out secret messages and what not) and the marker I was using was starting to dry up. I usually just wet my fingers and use them to wet the tip, but someone had left a small glass of water on the table so I instead dipped it into there (kind of reminds you of a feather and inkwell). After a while the marker would start to go dry again, so dipped it again....and again. I decided to let the marker soak up some of the water in hopes that it would last a little longer so I placed it in the glass and switched over to another colored marker. After about 5 or so minutes, I looked up and saw the water "glowing" a little. I placed my light closer and it started to really glow. That's when I discovered that highlighters make really cool effects when used in water.
Here's what you'll need:
1. Highlighter marker
2. Glass of warm water
Before I forget to add this in.... Warning: Don't drink the water unless you used non-toxic highlighters (even then it may not be a wise idea to do)
Step 1: Drain the Juices....
Make sure you have a glass filled halfway with warm water...
1. Take your highlighter apart so that you can get at the sponge.
2. Take the sponge out of the marker and cut off the plastic that surrounds it.
3. Drop the sponge into the water and watch as it absorbs the water while leaking out the ink.
4. After the sponge has absorbed as much water as it can, take it out and squeeze the contents back into the glass until the sponge is fairly dry.
5. Now turn off the lights and turn on your blacklight near the glass
Spooky.... Video below....
Watch for my next instructable for adding in a body part....