His mask, boots, and gloves were sculpted with a bakable glow-in-the-dark clay.  But because the clay picked up too much dirt from handling during the sculpting process, these parts were painted over with acrylic paints. 

After the whole figure was painted, he was sprayed with a clearish glow-in-the-dark spray paint.  I say clearish because it did leave a dull film on the whole figure.  But as you can see, the glow-in-the-dark spray didn't deminish the colors much at all.  And MAN, he looks good in the dark!  If I can figure out how to take a picture of him in the dark, I'll try to post it. 
 
 

I saw another figure on the web using this combo, and that figure inspired Chip to make this one.  I wasn't a member of the Customizing Listserv at the time, and I can't remember who it was or I would give him or her credit.  Let us know if you were the inspiration and you can see your name (and link) in print here.