is the ratio of solar heat gain through a given glazing system to that of a clear float glass of 1/8 inch (approx. 3mm) thickness under the same test conditions. Lower the shading co-efficient, better is the ability to reduce solar heat. Emissivity measures the surface ability to absorb or reflect Far Infrared Radiation. Lower the emissivity rating, better the insulating quality of the material. Glare Reduction is a measurement of the reduction in visible light transmission after applying the film to the system as compared to the visible light transmission earlier. (It is represented in%). Solar Heat Gain is the sum of percentage of solar energy that is either transmitted or absorbed and then re-radiated into the room.