I'm trying to find a way to do this as realistically as possible in Maya. I want my robot to be painted and the edges to be chipped, and worn to reveal a brushed steel type look. And in some places simply chipped...

I have a very detailed robot so I would like to do this somewhat procedurally. I want to be able to simply paint a black and white map to reveal the underlying brushed steel surface.

There doesn't seem to be a layered shader in maya so can I use the Mix8? How would I go about doing this? What would I plug my black and white map into?

Hoping someone who has experience with this could help me out, thanks...