Pentel Liquid Glass and Chalk Marker is a wet wipe marker for use on any smooth and sealed surface. After the pen is inflated by pressing the nib against the surface several times, the liquid ink inside can be used to write on most glass surfaces and other smooth surfaces such as mirrors or ceramic boards. When applied, the highly opaque water-based ink gives an effect similar to liquid chalk, which allows the user to create special effects. After drying, the ink is resistant to weather conditions on the glass. Wet Erase is a temporary marking marker that can be removed without leaving any residue. Pentel Liquid Glass and Chalk Marker has two types of tips. By rotating the tip you can get different width of the writing line. (The tip is cut on one side and round on the other). Ideal for use on glass (e.g. in car showrooms or glazing services), for customer announcements and decorative applications in retail (e.g. shop windows), in hotels and restaurants (e.g. menu boards) and in home projects (e.g. creative work on windows or glass objects). Important: The marker can leave permanent marks on surfaces that are porous or not completely smooth. It should be remembered that marker remnants may remain on the blackboard transparencies. Always test on an inconspicuous area first