Here is a window decal supplied by PENTAGON Security System 36 years ago. Then, 4 years ago, I applied infrared-blocking one-way mirror film made from polyethylene terephthalate (PET) to all windows of my house in order to keep house's interior cool in summer and warm in winter.
ATTENTION!
Ces lieux sont protégés par un système
d'ALARME ELECTRONIQUE
Decal's degraded area passes more incident light than the area with window film alone. Such anomaly is possibly due to window film's loss of construction components which blocks IR and UV components of incident light. Window films's construction components may be dyed, pigmented, metallised, ceramic, or nano.
