Another thing I found, I think it's best to use the plastic only once. The overspray won't flake off right away; but it might a few days later. I painted two cars within two weeks, and there was some contamination in the second car from old paint coming off the used plastic. I have one more car to paint, and I'll replace the plastic before. Plastic is really cheap, so it's worth replacing for each job, in my opinion.
81 Grand Prix, 355, 700r4, 8.5" 4.10
64 Oldsmobile Jetstar, all original