durable , specularly reflective mirrors for solar reflectors or fluorescent lamp fixtures are formed by vapor - depositing silver on a polyester film and protectively covering it with a coating of transparent acrylate polymer containing a silver corrosion inhibitor such as glycol dimercaptoacetate . in a preferred embodiment a pressure - sensitive mounting adhesive is applied to the opposite face of the polyester film . degradation of the polyester , and consequent bubbling of the adhesive , is reduced or eliminated by incorporating uv absorber in acrylate polymer that is applied as a second protective coating .