What kind of fabric to make curtains for a window?

I need to cover the window in front of my mixing position. I've been looking into velvet, thinking that was probably the best thing for the job. But then I started to question my reasoning. So...what do you guys think? What kind of fabric should I be looking at?

Acoustically - the heaviest you can find. I'd recommend 4" of 3 PCF mineral, rock, or fiberglass wool :wink: Steve

I also have been looking for a curtain myself... I thought about making curtains by wrapping fluffy pink from both sides, making them thin layers. A few of those stacked layers might make a nice MOVABLE squeezable curtains. but.... 4 layers of heavy fabric hanging might do just fine as well.