I've seen a lot of ideas from teachers about writing on student desktops with a Sharpie/paint pen and how easilythey come off. I have paint pen in hand, but I'm too chicken to take the final step. Lol have any of you done it? I'm wanting to label their jobs (just one or two letters) on the corner of their desk. It would stay all year. If you've used the pens, which did you use? Was it oil based? Thanks!!