Why dont you use vertex colors for the rusting?i mean like r=0--> painted, r=1-->rusted or something like this.then you could paint where you want rust, and where not.it would be a lot more customizable and realistic.
Might be misunderstanding your point, but you can hit the 'R' button in the tools palette next to Save Ztool, etc. to reset the palette. EDIT: Just to clarify, I mean the 'R' under the Lightbox > Tools button in the Tools palette, not next to the Go-Z button.
> Victor’s annual income is under $10,000 so much for being a c r e a t i v e p r o f e s s i o n a l instead of working for ikea or fulltiming at 7/11 for that matter