If you are a curious person, chances are you would have stopped to wonder why your car windscreen and windows have black dots at the sides. While those black dots look fashionable, they are actually not just for decoration.
Some of us however don’t give much thought to the pattern of little black dots on the edges of car and bus windows. While they look cool, you will be surprised to know that they are there for a reason.
As it turns out, we learned that those black dots on windshields and windows, and the black rims that surround them, do have a reason for being there (other than decoration). It has to do with how car windows are made—from the 1950s and ’60s onward, car manufacturers started to use an adhesive to hold car windows in place, rather than metal trim.
The adhesive they employed got the job done, but it wasn’t very aesthetically pleasing. That is where the black rims that you see around car windows, called “frits” came about.
The frits (and the dots that border them) are made from ceramic paint. The frits are there to hide the rather icky-looking, but very important, adhesive from view. More so, since these painted rims are baked into the window, they are all but indestructible. They hold the glue in place, which in turn holds the windows in place.
As for the dots, they are there to make an aesthetically pleasing transition from the thick black lines to the transparency of the window. The dots are not randomly placed; as a matter of fact, they are positioned in what’s known as a “halftone pattern,” getting smaller and farther apart as the black recedes.
This pattern is less jarring to the eye than opaque black paint juxtaposed with transparent glass. The other purpose of the black dots, besides the visual effect, is to provide temperature control.
To get the glass of windows and windscreens to be bent the way it is, the glass is heated up. The black-painted glass heats up faster than the rest of the window. The dots are there to distribute the heat a little more evenly, which prevents the windshield from warping in the heat.