Unveiling the purpose of obscure black dots on car windows

To understand their function, let's look at the process of installing car windows. When glass panes are fitted onto a car, their edges are covered with ceramic paint and then subjected to heat. This treatment is intended to create a rough surface, to which the adhesive can firmly stick.

During this heating process, the ceramic paint reaches a final temperature that is significantly hotter than the glass. The black dots are strategically placed on the edges of the window to prevent a large temperature discrepancy in a small area of the window, which could potentially cause damage. This is the reason why the dots differ in size, enabling a gradual change in temperature.

However, that's not the only function these small black dots serve. They also form part of what is known as the frit, or the black border of the window. The role of the frit is to hide the adhesive used for window installation. Moreover, it shelters the adhesive from the detrimental effects of ultraviolet rays, thus extending its lifespan. Consequently, this helps in maintaining the durability and safety of the car's window.