There is a common misconception with window tint that it is all the same. Well I am here to tell you that it is not. Most people think that it is ok to apply an automotive film to a commercial window and they would be wrong. The reason you cannot or it is not recommended is because auto glass is tempered and is designed to take and hold heat, while commercial glass is either a single pane glass or dual pane glass and it is typically not tempered. If you apply a piece of film that is just dark without reflective properties then all of that heat is absorbed into the glass instead of reflected off of it and you might cause a thermal stress fracture to the glass. This means the glass could crack because it has absorbed too much heat which causes the glass to expand and contract and might cause it to break. There are many different films in a variety of different shades that are safe and approved to install on your commercial or residential property, just call your favorite tint supplier (tintdepot.com) and they will be able to recommend a film that will suit your needs. My personal favorite is the Dual Reflective series!