🎨 Paints - Fluorescents
Fluorescent paints glow a bit in the UV light. Of course this differs from brand to brand but fluorescent paints have intense colors but are extra transparent.
Fluorescent paints look intense because of the transparency and binder consistency; more layers of the pigment get reflected into your eyes.
Fluorescent paints frequently have a slightly gel-like consistency. This can make them hard to use but remember that they are super transparent, so it won't look as overpowering after it dries.
You would usually use only one or two fluorescent paints per model and in such colors that contrast with the rest of the colors on the miniature. Otherwise, the effect has less of an impact and might look chaotic.
Like always, you can go to town with only using fluorescents but that's rare.
You can glaze with fluorescent paints. You can basecoat an area with whites and greys; and then apply a fluorescent to make it glow. Like a torch or magic rune. Make sure you also glaze it bit on the surrounding areas to improve the glow effect.
You can also airbrush thinned fluorescent paint. Gives you smoother transition.
You can do feathering with fluorescent paints. You can place an unthinned blob of a fluorescent paint on an area (so it actually has some volume) and use a brush to stroke it outwards to get an intense glow transition. Kinda like feathering.
You can mix fluorescent paints with normal paints. It will make them glow a bit. This is the way you can use fluorescent paints for shading and highlighting as the fluorescent product lines are very limited.
If you are mixing in fluorescents, you should mix them to all layers of paint from the basecoat to the highest highlight. Otherwise, some parts will not have any glow, and it won't look good as a whole.