Blackboards are very nice:
- You dont have to put out a lot of paper
- you can clear it
- poster-sice or wall-sice
- visible for everyone who comes in the rooom (topics of conversation)
- a green wall is comforting the temper
You can get a lacquer (waterbase) for wood, plastic, metal, wall, ..
You can also get a plastic film for the wall, wood, metal,..
I use the plastic film i combi with a balsa-wook-plate (lightweight) and a cucent film.
With that i have a protabe blackboard.