What the black dots on a car windscreen are for

If you’ve ever sat in a car and looked closely at the edge of the windscreen, you might have noticed a pattern of small black dots arranged in a very specific way.

While they might seem like a simple design feature, these teeny tiny dots serve an important purpose in both aesthetics and functionality.

The black dots are part of a ceramic black paint layer baked into the glass during manufacturing called the “frit”.

Primarily found around the edge of the windscreen, the frits usually extends inward in a dot-like pattern known as the “dot matrix”.

The dot matrix is a really good example of smart engineering and even though you’ve probably never noticed it before, it’s doing an excellent job of protecting both you and your windscreen.

Considering how vital these little black dots are, drivers are only now just realising what they do. On Reddit, many have asked “what are these black dots?”.

One contributer said: “Thank you for asking this because I have been wondering for a while, but always forget to ask.” Another cheered: “Yes! I always wondered too, but never think to ask.”

According to windscreen experts at Autoglaze, these underrated black dots help distribute temperature evenly.

Without them, the solid black band (the frit) heats up much faster than the rest of the windscreen. The less black there is on the glass, the less heat it absorbs and the areas without black don’t get hot at all.

This is why the dots gradually fade out to help distribute the heat more evenly to prevent distortion or even cracking.

Frits also help prevent windscreens from cracking by protecting the adhesive that bonds the glass to the car frame, reducing the risk of the glue weakening due to heat or UV exposure.

This subtle vehicle design feature has some other pretty useful functions too.

The dots help the glass bond to the car frame by creating a rough surface, allowing the adhesive to stick more securely. Finally, frits help to improve the look of the windscreen, enhancing their appearance.

Without them, the contrast between the black band and clear glass would be too noticeable, whereas the dot pattern creates a gradual fade, making the transition smoother and easier on the eyes.

The Highway Code states that drivers must have a clear view of the road ahead, and that all glass in the vehicle must be in good condition. A cracked windscreen can make it unsafe to drive and could be considered a motoring offense.