- George Poland
What are the black dots on your windscreen?
We’ve all seen them before, but have you ever stopped to think what the tiny black dots on your windscreen do or why they’re there? It turns out, they serve a few important purposes.
The solid black band that covers the sides of your car window is actually called a ‘frit’. The frit is ceramic paint that has been baked into the glass during the assembly process, meaning it cannot be scraped off.
One of the frits’ main jobs is acting as a filter to stop UV rays from damaging the urethane sealant that fixes the glass into position.
If the frit wasn’t present then the sealant would be more exposed, resulting in gradual deterioration and damage over time and risking displacement which would be damaging and dangerous to your vehicle.
Not only does it protect the sealant, the frit provides a rougher contact point between the car frame and the glass allowing for the adhesive to glue itself better to the glass.
These familiar fading black dots hold two other purposes. Firstly they help to even out the heat distribution during the manufacturing process that’s called ‘baking’.
Without the black dots there would be an excessive amount of heat concentrated in the black edges causing visual distortions to the glass.
The other purpose for the dots is for aesthetics. This is why there is a slight gradient if you look closely. Black dots that fade makes the frits more easy on the eye than a harsh black border. The solid black colour also helps to cover up any marks or scratches left by the adhesive.
However, none of this explains why there is a large concentration of black dots around the base of the rear view mirror. This patch of dots is called the ‘third visor frit’.
The third visor frit helps to defuse the sunlight out of your eyes when you’re trying to look at your rear view mirror. A simple yet very effective feature that you may not have been aware about.