By far the most asked question, unfortunately, the way that films provide privacy is through lighting, by blocking light from outside during the day it becomes easy to look out and hard to peek in. Those same conditions are drastically flipped at night, with no exterior light source and often lights turned on indoors now it is all backward and you allow visibility from outside but it becomes hard to look out from inside. The only option that works at all hours is frosted films which allow light in and obscure both sides of the glass. 

Window films reject 99% of UV rays which accounts for about 40% of fading from the sun, the other contributors are visible light and heat as well as 10% of miscellaneous factors meaning that the more heat and visible light is reduced the more fading is prevented with up to 95% reduction with one of our highest performing films. 

Window tinting does not affect your dual-pane glass as long as you follow these simple rules. Any film darker than 30% Visible light transmission MUST be reflective, lighter than that you can apply any neutral film from 30-90%.  This percentage is a measurement of light that's allowed through the glass so 5% is very dark whereas 90% is clear. 

All interior applications come with a lifetime warranty for residential and 15 years for commercial applications. Films really last a very long time indoors, however, for those with dual-pane glass, the seals containing gas between panes have a life of between 18-35 years so your dual pane is most likely to be replaced before the film. Single-pane windows do not require replacement as frequently.