We do not recommend using Mylar® brand (polyester film) for outdoor applications. Although it may be suitable for short term projects, it is not geared to tolerate sunlight over long periods of time. Long term exposure to the elements can cause the film to yellow, become brittle or turn hazy. The best product that we stock for outdoor use is HDPE and Polypropylene. It is possible to custom manufacture Mylar® brand (polyester film) with UV inhibitors on a custom basis, but steep minimum orders will kick in. Contact us today to discuss your requirements for outdoor films.