I would caution against Mylar. Who knows what will happen when you freeze or heat the soft, thick, blistered clear to remove it. I'm going to get some acrylic washers that are just out of ball range. My theory is that over time, the blistering (I have very little) will settle flat. Then I'll remove the large washers and put on smaller ones. Hopefully the clear can/will cure close to flat. This is all assuming I can find the damned washers...