Best mt bike fabrics (brush & briers) ?

[Miranda]

I'm primarily a road rider, and my cycling wardrobe reflects this (lycra). I recently starting doing some mt biking. For lack of owning proper mt bike gear, I wore some of my road clothes. Any of you mt biker gals know that lycra and briers, tree branches, brush etc. do not mix well.

I have seen on line some mt bike specific shorts that say the fabric is nylon based. Which I know would fair better with briers. I have yet to come across tops that specify this. I wore just a long sleeve cotton T-shirt over one of my silky fabric road tops last ride. The cotton doesn't wick sweat so well, but kept my silkly fabric top underneath more protected (as well as my skin).

Can you suggest some brands, or specific items, and/or ANY tips really to help on what to wear in the brush?

Thanks!
Miranda