Window film technology
Window Film Microsphere
Microspheres are tiny glass or ceramic beads sometimes embedded in window films to scatter infrared light, contributing to overall heat rejection without affecting visible clarity.
Microsphere additives target specific IR bands by Mie scattering. The bead size is tuned to scatter infrared while letting visible light pass — a principle similar to nano-particle rejection but using a different physics.
Microsphere films are less common than pure nano-ceramic, but they appear in some hybrid formulations as a complementary IR-rejection layer.
For end consumers, the chemistry detail matters less than the headline heat-rejection and IRR numbers. Reputable workshops can name the chemistries in the films they install.