Some of our racks have this stuff called Texturelac
which is an industrial spray paint that can be applied in a variety of different finishes depending on the amount of liquid to air mixture when you're spraying it on.
We also have used (when we're in a rush) that stuff you can pick up at Home Depot called American Accents
... We use the Stone Creations finish spray paint in a can. This enamel paint is made by Rust-Oleum and works very well when applied correctly.
The third type of finish was applied by the Big Deal Custom Casings.
They built all our lastest cases. They're located in Canada.
I hope this helps!