[Bruzilla]

I just saw a commercial for this stuff. It's a silicone-based dough that glows. Apparently it's like Sculpy and will stay soft until you bake it to make it hard, and it still glows afterwards. I can see some interesting applications for this!

https://www.lumidough.com/

 

[UnOrthodOx]

I've seen the commercial, but haven't played with it.

 

[Loene]

Another way to go is build what ever you want and then get glow in the dark spray paint. It works well. I also used it on T-shirts for under a black light