Some of the more accomplished makers might correct me, but basically no matter the material the 'weights' are the same. It's how heavy a yard of the material is no matter what it's made of.

Now I would imagine depending on the material at certain weights you see a difference in the way it flows and folds, some materials being stiffer than others. Most of the PV kilts made will be in the 11-13 ox range I believe.