Review on VELIMAX Blackout Window Film – 100% Light Blocking Cover, Opaque Vinyl Cling, Privacy Film for Glass Windows, Sun Blocking Films Without Adhesive – 17.7in x 78.7in by Samantha Cook

On a sunny day or in a dark cave, this product does an excellent job of blocking out the light. It was easy for me to apply and I did it myself.1. Clear window 2. Cut the material to fit the window 3. Spray the window thoroughly with soapy water. Be sure to wet the entire window.4. Remove the protective film from the material.5. Starting at the top of the window, press the material against the glass, pressing firmly, then use a credit card to squeeze out any air bubbles. Wipe off excess water and trim the edges with a razor blade as needed. So after about a week I realized that I hadn't cut the material perfectly and light was leaking through the edges. I took duct tape and ran it around the edges of the window, and then I took white tape and sealed it with duct tape. This resulted in a 100% reduction in ambient light.