HELP/PAINT: Before applying, how smooth does the surface need to be?

Writeyboard 1-Part Dry Erase Paint will fill common sanded previously paint-roller texture. Remember that the surface needs to be smooth enough to write on and erase. A typical lightly sanded dust-free paint-rolled wall will work perfectly! If the wall has a wall textured finish, simply lightly sand down the texture to a smooth surface, remove the dust, make certain the surface is dry, then paint with your 1-Part Dry Erase Paint.