Hello, I am building some acoustic panels using Roxul (mineral wool). I am going to buy fabric to cover them and today I was at the fabric store. The girl showed me speaker fabric but when doing the blow test I didn't think it allows a lot of air through. She also showed me Athletic wear and that actually allows way more air when you blow. My only concern is that having little holes (athletic wear does of course) may not be good because with time fibers from the insulation materials will pass through. As you imagine I spend most of my life in the recording/mixing room so I am worried about the health hazards of this. The question is: Do you know about Roxul use in long term? and also should choose Speaker fabric instead? Athletic wear is not only cheaper but allows more air. Any insights are appreciated. Thanks.