Every driver is familiar with the black edging with black dots on the windshield such as scrap cars for cash. But why are manufacturers actually using it?
The black frame around the windshield with black dots can protect our eyes from the sun if it’s wide enough at the top, but that’s not what it’s for. The black outline is not a sticker at all.
Why black dots around windows?
It is applied to glass by screen printing, made of ceramic enamel, which is sintered with glass at a high temperature. This is the key to securing the windows in the car, which are attached with glue. If it were not for this black edging, it would be impossible to properly attach the glass. This role is primarily played by the inner side of the frit. The external is also important, its task is to protect the adhesive from solar radiation and ensure the durability of the joint. The black border also has a purely aesthetic task – it hides the glue from our eyes.
What are these black dots for? They are designed to prevent large temperature differences over a small area of the glass that could damage the glass. The dots prevent the formation of optical distortion due to the fact that the frit heats up faster than the rest of the glass. They have one more task.
On the other hand, the black dots that sometimes appear around the rearview mirror are plotted based on the direction of the driver’s gaze. They are mainly designed to prevent glare. They cover the area on the glass that the sun visors cannot cover. Thus, the black stripe is, from the driver’s point of view, just one of the little things. This is important for manufacturers, but for us ordinary drivers, it doesn’t really matter. We don’t need to worry about it, but it is certainly helpful to know why these black dots are applied.