First we spray the Coca-Cola and then we stick a kitchen foil paper layer until cover the surface of the window. The shiniest side have to face the exterior, the matt to the interior.
This is a polarization method used in the mexican side of the Sonoran Desert. We decided to reproduce it on the entrance of the Kunstverein of Rosa Luxemburg Platz. The installation worked as a threshold between the outdoor light and the indoor dark.