There are two main types of dust-free blackboards, also known as environmentally friendly blackboards: one is using liquid pens for blackboard writing, and the other is using chalk for blackboard writing. When writing on a liquid pen tablet, the writing board is white or beige. The advantage is that it does not shed dust. The drawback is that the cost of using consumables is a bit high. There are two types of dust-free chalkboards that use chalk to write. One is dry erase writing, which is the traditional dust-free chalk writing board. When wiping, chalk dust will fall off. However, the difference between it and old-fashioned chalkboards is that there is not as much dust and it will not float in the air. It will fall into the chalk slot along the chalkboard for easy cleaning. The second type is the popular wet wipe dust-free blackboard in recent years, which is based on a conventional board with a layer of wallpaper like blackboard film attached to the surface. After the film is applied, it can be used for writing separately or with water-soluble fixed chalk. What is water-soluble solid chalk? It is a type of chalk similar to crayons that cannot be wiped off after writing, and can only be erased with a damp cloth or water. This board feels more environmentally friendly and dust-free compared to conventional blackboards, but its shortcomings lie in wet wiping. After wet wiping, writing cannot be done immediately, and it needs to be dried or air dried before writing again. Moreover, because it often needs to be wiped with water, the board is in a humid environment for a long time, and its lifespan is not as long as dry wiping dust-free boards. The lifespan of this board is generally around 3-5 years, while the lifespan of dry wiping dust-free boards is generally 8-10 years or more. Imported boards have a lifespan of up to 50 years or more, so currently the most convenient one is still the traditional dry wiping dust-free blackboard