Most drivers will have noticed the pattern of black dots at the edge of a car windscreen, but many are unaware of the major role played by the tiny markings. Known as the ‘frit’, these dots are vital in protecting the windscreen and the vehicle itself.
A spokesman from Motor Match said: “The black dots, often called the dot matrix, have a significant function when it comes to heat distribution. Without them, the solid black frit band around the edges of the windscreen would heat up much faster than the rest of the glass, leading to distortions in your view.
“ou might notice straight lines appearing bent or warped if the glass heats unevenly. The dots help dissipate the heat gradually, so the windscreen heats evenly and prevents this effect.”
In addition to managing heat, the frit also holds the windscreen securely in place. “When vehicle manufacturers transitioned from metal trim to adhesives in the mid-20th century, the frit became essential,” the expert continues.
“It provides a rough surface for the adhesive to bond, so the windscreen remains firmly attached to the car’s frame. Without this feature, the windscreen’s structural integrity would be compromised, especially under the stress of high speeds or impacts.”
The frit band also offers protection against UV rays, which can degrade the adhesive over time. “The enamel acts as a shield, preventing the sun’s rays from breaking down the adhesive that holds the glass in place. This helps the windscreen remain secure for years, even in harsh weather conditions,” the specialist said.