Zbrush mask material?

Borx25

Hi, is there a way to mask by materials, or convert the material to polypaint so i can mask by hue/intensity, or make polygroups by materials, i don't know, there must be a way to do it, right?

Also in that model i have layers, so if there is a way to mask the polys a layer modifies then i can use that too.

I have a model in wich i made a mask and recorded in a layer a inflate of that mask, to make engravings and be able to change their depth, also changed their material, but didn't saved that mask as a polygroup or polypaint, now i need that mask, any ideas?

thanks in advance