I bought some phosphorescent gouache. I had no idea of the real effects of such a product in the dark, and i was quite disappointed. I didn't know what to do with it, and instead of throwing everything away, I managed to save the phosphorescent pigment in it.
This kind of pigment can easily be bought on the internet, so if you want some, just buy it. Don't do all this mess.
It's gouache, so i think it is meant to be used by children, without any protection and i didn't find any hazard symbol, but I suggest you try this in a ventilated place and use gloves.
Step 1: Decantation
It really looks like a chemistry practical work for young teenagers actually.
Just add some gouache and water in a jar.
Shake and wait. After a few minutes, all the pigment should be clearly apparent at the bottom.
Step 2: Removing Gouache
Slowly empty your jar to keep the pigment and get rid of water and gouache.
There may be still some gouache in your container, so add water again and repeat the process to get something clearer.
Step 3: Dry
Slowly remove as much water as you can but don't let pigment escape the jar.
Now, you can wait for the remaining water to evaporate by itself, or use any hand-dryer, hair-dryer you have to make the process faster.
Step 4: Almost Done
Use a spoon to scratch the powder. Its color only depends on the number of times you repeated step 2.
With a cone made of paper, you can make a cheap funnel, to help you fill your powder in the flask of your choice.
And that's it. Phosphorescent pigment you can use in any kind of project.
Step 5: Example
It's not really bright, so it's hard to post videos or pictures of it.
In this jar, there is : water / blue colorant / mica powder / the phosphorescent pigment.
When there is light, what you see is the mica powder, and when you turn the light off and you are in a dark place, the jar emits a little green light.
The problem with this mix is that the pigment is heavier than the mica powder, so after a few minutes, only the bottom of the jar is visible in the dark.
That's still something fun to play with :)