A must for film users!

I have tried some of OHP pens and am now "stuck" in these. I can only agree with previous speakers that! There are super colors (not only on the film, but also on the projected object), which also not too light blur when drankommt accidentally. They should not be left too long on the slide only when you want to use the films again. I've made the experience that but some residues remain when wiping, if you want to remove the color after eternal weeks (preferably immediately after use with a damp cloth)., But that's all nonpermantenten OHP markers so