If you have been driving for a while or have driven multiple cars in your life, you cannot help but notice that every windscreen has a particular array of black dots that surround the edge of the glass.

They typically appear on not only the windscreen itself but also the side windows, and sometimes the rear view window as well.

Besides looking quite aesthetically pleasing, the black dots, also collectively known as the frit band also have a number of important purposes as well for windscreen replacement services.

The black dots consist of a black paint baked into the glass that provides a vital contact point between the frame of the car and the glass. This paint is rougher than the smooth glass surface and so provides a much better point of contact for the adhesive to stick to it.

As well as this, it helps preserve the sealant against the effects of the sun, stopping the windscreen from simply popping out due to the glue being melted as the windscreen conducts heat. The frit band stops this from being the case.

Without the frit band, a hot summer’s day and a pothole could cause the entire windscreen to fly out, which would make the car dangerous to drive.

They also help to stop a phenomenon known as “lensing”, which is where the windscreen glass warps slightly as the frit band heats up quicker than the glass itself, which makes straight lines look curved on the windscreen, affecting visibility.

The arrangement of dots helps mitigate this effect and spreads out the heat more evenly, avoiding potentially dangerous levels of distortion.

Finally, the dot pattern itself hides the adhesive, making the windscreen look nicer than it would if it was simply a black band that was obviously used to stick the windscreen to the car’s frame.