Please take the time to vote! (hopefully for me).
This is my photo Instructable on my experiences making black light nail polish, paint, or anything for that matter!
I will also explain how to make it, seeing as it is quite simple.
-Find some detergent (maybe look near your laundry machine :D).
-Find a black light (they come with those "invisible diaries" for cheap if you don't already have one).
-Test your detergent in a dark room to see if it glows (it is easier to put some on your fingers and shine the light on it instead of straight into the bottle). If your detergent does not glow, try a different brand.
-Mix your detergent with; A) Clear nail polish (or coloured), B) Water based paint, C) Whatever else you want to GLOW!!! (you can also just paint it right onto a surface for a party or something of that sort (plus: automatic party cleanup once wiped up with a wet rag!)). If mixing with something (such as paint) stir it in until the mixture is consistent. If using nail polish, you can shake it directly in the original bottle.
Why does it glow? Some detergents contain bluing agents used to make clothes brighter, and they react to a black light.
Paint; 1 cup of paint to 1 tbsp. laundry detergent.
Nail Polish; 1/2 tsp. to 3/4 of a bottle of nail polish.
Note: If the glow is too faint, add more detergent until it glows to your satisfaction.
It is also a good idea to keep track of how much detergent you add so that you can mix a larger batch, if you need to, using the same ratio.
Don't forget to vote! (hopefully for me!)