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Whilst shaving the excess cured resin during this repair, the solar reflective coating became visible under the light in the workshop.

This particular windscreen is heated (embedded within the sandwich construction of the windscreen is a mesh of very thin heating wires which you will see in the image if you look closely; another more modern version of this is heated chemically via a silver/zinc oxide coated film within the glass).
Also within this windscreen’s layers is a ‘solar reflective’ coating (also known as solar reflective or athermic). Solar glass will allow sunlight to pass through it while radiating and reflecting away a large degree of the sun’s heat. This windscreen is also a HUD variant meaning it has a ‘wedge piece’ integrated within the PVB interlayer, This effectively is the surface onto which the image is projected. It also negates the ghosting effect you get on normal glass.