Colouring: yes and no
The legislation is mainly concerned with car windows’ transparency. The windscreen and side windows in the front must have a minimum of 70% transparency, otherwise the car cannot be driven on the roads. “That’s why various third-party films that darken the windows are problematic,” explains Sluka. Simply put, the front windows cannot be tinted. A certain level of opacity (up to 30%) is provided by the glass material itself and maybe the presence of windscreen heating technology.
The windscreen heating with a thin tungsten wires has a very subtle structure that in no way impairs the view.
“The film between the two layers of glass can contain thin tungsten wires, while a more modern solution is a thin metal layer applied essentially by steaming,” says Sluka. Škoda uses both solutions, with Fabia, Scala and Kamiq customers able to order heated windscreens with thin wires, while other models (from the Octavia upwards) feature a metal layer solution. “For many drivers, this is easier on the eyes. Even if the wires are not normally perceived by the driver, they can be distracting for some,” Sluka points out.
The Škoda Scala, here in the Monte Carlo version, has distinctively shaped glazing in the boot door, with the glass extending to below the brand logo.
The windscreen must provide a good view not only for the driver, but also for any cameras and other sensors the car has fitted under the windscreen. At the same time, the windscreen is now an important “projection” surface for modern head-up displays. In these windows, there is a special film that compensates for image doubling, also known as ghosting. Also important is the shape of the window, which should not contribute to the distortion of the image.
While good vision is a priority at the front, at the back designers come up with various functional compromises for the glass. “With tinting, it’s all about making the cars’ occupants feel comfortable in the car. Too dark a window could create too dark an atmosphere inside the car,” says Sluka, adding that this is what Škoda’s designers had to think about with the Sunset package, which features tinted windows. Again, tinting can be achieved in two ways: either by adding a coloured pigment directly to the molten glass, or by using a coloured film that forms the inner layer of the laminated glass.
In modern cars the windscreen doesn’t have to ensure a good view just for the driver, but also for various assistance system sensors and cameras.