Hamburg  - "Mirror, mirror on the wall, who's the fairest of them all?" Many computer users find themselves in the same position as the Queen in Snow White: looking into a mirror. The difference: This mirror is intended to be a computer screen. Laptops in particular are known for having glossy displays that purportedly provide brilliant colours. Ultimately, though, glossy displays are not particularly practical.

While glossy displays may be perfectly adequate for working in enclosed spaces, they are infuriating outside, particularly in bright sunshine. It's torture on the eyes at best, and impossible at worst. Glossy displays are impractical and non-ergonomic, says Klaus Dembowski, a trained engineer at the Institute for Microsystem Technology at the Technical University of Hamburg-Harburg.

"That applies to displays with piano lacquer frames as well," the non-fiction author notes.

Special films have been developed to reduce glare problems. These cover the entire screen surface and take away the glossiness. There are two types of anti-glare: "One involves a matte surface, while the other is a so-called thin film, which has a light violet colouration," explains Kay-Uwe Schenke from 3M.

3M's Vikuiti ARMR-200 anti-reflection film is actually doubly anti-mirroring. One variant that can be laminated on the display is called ARMP-200. The film costs between 25 and 60 dollars, depending on the display size. A test by Hanover-based c't magazine determined that the films cannot fully resolve the reflection structures.

"The intensity of the mirroring is significantly reduced, though," says Schenke. Depending on the laptop, the application of these films reduces the brightness by no more than one to three per cent. The contrast was diminished on a test device only from 545:1 to 505:1. Otherwise the film appeared to be colour neutral.

Anti-reflection products can be applied to the display either on your own or by trained technicians. "You can either do it manually or send the laptop into the shop," Schenke says. The biggest challenge is getting the surface free of dirt and dust and then applying the film carefully with a spatula to avoid bubbles.

"Most people do it themselves," says Schenke. The testers at c't see the application of a self-adhesive film as a "difficult matter," especially since it needs to be pressed on with uniform force and speed.

"If it's applied even slightly crooked, then it leaves a reflective area open, which then is all the more disruptive; furthermore even the smallest air pockets or dust particles under the film are distracting," the testers warn.

They therefore recommend having a workshop perform the application, which costs around 100 dollars including materials.

While self-applied films can be easily removed again, laminated versions form a firm bond with the old display surface, known as a polarizer. Those cannot be removed without taking the old surface with it. As the lamination process at a workshop often involves the removal of the so-called panel, check with your laptop maker first about whether that procedure will void the warranty. (dpa)