A: The reason why we provide water pen is to make sure the reuse of both white board and plastic egg. To avoid the problem mentioned in the question, you can use a permanent maker pen which can only be erased with ethyl alcohol (alcohol concentration>95%) or acetone.
The pen comes with the mDrawBot is a water marker pen, which may be erased accidently. Any solution for this?
I use Sharpie Ultra Fine Point Permanent Markers instead. It is a bit higher quality and works well with slick paper. (Regular paper might bleed a bit, but does work.)