Okay, I have my new "outside" arena just about complete, footing, lights, and should be putting up dressage letters this weekend. I would really love to install a couple mirrors since they are so helpful when schooling and am wondering if anyone has used the sheets of mylar attached to wood as an option? I am looking at 4' x 8' foot arcrylic mirrors and they run around 300+ each, but if the mylar works that could be a cost saving option.