Removability, whether dry or wet, is always a problem with plastics of any kind. In contrast to glass, experience has shown that the surface is very sensitive to scratches. Even the soft tips of our markers can leave scratches on the surface. When rubbed with a cloth for cleaning, a kind of sanding effect is created with the help of the colour particles. Although the roughening is only minimal, it can be sufficient to allow further colour particles to settle. These colour particles can then no longer be removed without leaving any residue. We would therefore not recommend the described application.