Clear boards?

Having grown up around, beside–and occasionally inside–televisions, I’ve seen my share of movies and commercials, many of which happen to deal with math. Whenever I catch the season’s hottest differentiating flick (“difs”), however, I have invariably found the following scenario played out: a slightly eccentric professor is standing in front of the class scrawling miles of equations… ON A CLEAR BOARD. A CLEAR BOARD! A CLEAR…ahhh, you get it. This is driving me crazy. No one has been able to provide a satisfactory response to the following questions:

  • What is this clear material?
  • What does one use to write on it? (e.g. dry-erase markers, grease pencil, mascara…)
  • Why does it have to be clear? Are there any distinct advantages a transparent board has over a white board or the classic chalkboard?
  • Is this board actually used outside of Hollywood? If so, why is it exclusive to science and mathematics instructors?
  • …and… uh… what is the cost of this material, say, per sq. foot? Or panel. Whatever they sell these things by… (cubits?)

I’m losing weight. I can’t sleep at night. My friends and family say I’m starting to withdraw.

Please advise.

This was actually discussed recently, in reference to Good Will Hunting, IIRC. You could try doing a search, but I’m pretty sure the consensus was that grease pencil is probably the best for writing on glass. Dry erase also works relatively well on glass.

The only purpose of using a clear board is for the viewer. It allows the actor to write (backwards) without obstructing the camera’s view of the text. Also, it looks cool.

In addition to grease pencils and dry-erase pens, there are pens designed specifically for writing on glass; in my favourite movie, Amelie, the (delicious) Audrey Tatou uses one to write a daily menu on a glass partition in the café-tabac where she(or rather, her titular character) works.

In movies, as friedo suggests, the main use seems to be that we can see the character face-on, at the same time as seeing what he/she is writing.