A white board
is similar to a chalk board
, only you use nifty colored markers
to write instead of chalk
. The markers posess a special ink
that adheres loosely to the surface
of the board, known as dry-erase
ink. Once the ink's solvent evaporate
s, the ink is easily remove
d from the board
with a normal felt eraser
. It becomes a fine
powder that is much less messy
than chalk dust
Whiteboards are popular with people who are allergic to chalk, and also in computer environments where the much lighter and messier chalkdust gets into equipment. They also provide better contrast than chalk boards if you use high quality markers.
Sometimes someone will accidentally use a permanent marker on a whiteboard. Fortunately, the only difference between dry-erase and permanent marker ink is that the permanent marker ink adheres more strongly. The solvents are so similar that you can erase permanent marker by simply writing over it with a dry-erase marker and then wiping it clean.