They sell light reflective paints, but some can be pretty expensive.
I do like to use the neon colors it comes in,
but I make my own white.
It's not as bright and it does fade over time, but its easy and cheap!
You can actually see more of the detail lines in person... but I had to turn off my flash
so they are lost in the pictures.
I use a mixture of Acrylic Gesso and Liguid Laundry detergent.
Gesso can be found in the paint section of the craft store. I buy the big tub but it also comes in small affordable tubes as well.
Tide is well known to be black light reactive by itself, also I like this stuff called Vivid.
It works really good and it's about half the price.
If you have liquid laundry soap on hand, check it out. Some brands glow, some don't.
I do a mix of approximately 2 parts soap to 1 part gesso, and mix it really good.
First I start with a pieces of black poster board.
I trace my drawing with a white pencil.
I apply a coat of just the Gesso....sometimes I do 2 coats depends.
Then I apply the Soap/ Gesso mixture..
about two coats should do it.
This image is simple but for more complicated pictures I use my projector, trace the image then paint the Geeso, and trace over it again.
Here I only painted half so you see the contrast of plain gesso and the soap mixture.
See it glows great! And mixing it with the Gesso makes it thicker and easier to paint with than just going with straight tide over your painting.
I like to do the final coat in the black light to catch any missed spots.
It does fad ever time so my black light paintings I just go over again close to the big night with just soap, while under black light and it brightens right back up. And the guides lines are already there so it's easy.
Here is another one I am working on.
He doesn't show up on camera as good in the black light for some reason...it looks purple here, but in real life his skin is the same color as my skeleton.... my camera is crap.
Someday I will be able to buy the real good paints, but until then this poor man's version will work.