I've told you before and I will tell you again, try the Vestax box bag. I think they were the first company to make the bags commercially (although I am not 100% deffinate about this fact!) and look like they are tough as old boots.
Fill out this form and your posting will get whisked away to a secret hiding place where our trained ninji (plural for ninja) will frown at it, poke at it, and hopefully approve it.