The whiteboard pen contains chemical materials and will have the smell of chemical materials. After the ink solidifies, a layer of mucous membrane forms on the surface. After wiping, it becomes a strip or a block of particles. When writing intermittently, may not need to put on the pen cover, never dry head, writes smoothly like. In the same industry in the leading level of the pen after dipping into the water can still write smoothly without a cover to completely expose the pen head in the air, no matter how long it can be written smoothly again.