(1) Does not melt even in summer heat. (Heat resistant up to 176°F (80°C) or higher) (our conventional products melt in about 50°C (for example, in mid-summer cars)) (2) Water-based type. It will disappear after you apply water and scrub it hard. (It will disappear under rain or water) (will not write on wet glass or plastic) (water may not be easily dripped depending on wood type and glass surface conditions. Please test it before use)