Prevent markers from spoiling projector screens

[p_thejaswi]

How many times have we seen ugly marks on overhead screen projectors?
A simple idea would be to place a (fixed) glass/plastic fibre sheet in front of the area of the screen. That way, when someone (unknowingly) tries to use a marker on the white screen, the damage is not done!!!

[L.Malone]

Sounds like a good idea. Prevention is usually more important than a cure.

It might work better if a material could be found or invented that would work both as a surface that could be written on and work equally as well as a screen.

This would have the advantage of allowing an instructor to project directly onto the surface and then add notes to the image being shown.

I believe the surface would need to be slick enough to be written on without reflecting too much light back.

[Dinoduck94]

Sounds like a good idea, we always come across that problem at school. But i think that once it has been written on then what happens after that, can the material be washed so the marks are washed off and can be easily used again, or does it just rub off like a whiteboard (but then there are usually still makrs left o a white board)