As Mr. MacLeish mentioned 3M is the brand to go for. They have several films to choose from, and all the necessary data (and data sheets) for your museum. I had one of their films applied to a very large set of windows in our museum seven years ago and it has done very well. A couple of times a year I will borrow a spectrometer from one of our science labs on campus to make sure its not degrading, and in 7 years it hasn't allowed in a bit of UV or IR. (It's rated for a 10 year lifespan)
Look up local window tinting companies in your area and find one that is a licensed 3M dealer.
Good luck!
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Alan Rideout
Head Preparator, Museum Photographer
University of Kentucky Art Museum
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