source for speaker grill cloth

I need to get some of that plain black fabric they use to put over speakers. You know the stuff, it stetches out to where you can almost see through it but not quite.

I need to put some over some speaker boxes I've got but can't find it anywhere.

Any suggestions? I'd prefer a store that I could get it rather than online (since I need it soon) but either will do.

ideas?

go to your local fabric/craft store, thats where i got mine

Radio Shack has it.