I use those white throw away masks. Sanding with any kind of power sander creates a lot of dust. I have thought about getting a better mask, but can't justify it for the low output that I produce in terms of scale production. I also however have a shop vac which I hook up to my various power tools. With my belt sander it works wonders... literally no dust anywhere outside of the vac itself! So sometimes I don't even use a mask, although lately I have thought about it in concern for safety more and used one. I even hold the shop vac tube sometimes while sanding with the dremel. It takes a lot of that wood dust out of the air. Sorry we're getting a little off topic.