Product Introduction: This chaco pen will disappear naturally over time and can be erased even with water. Product Description: Water-based chalk pen that disappears quickly and naturally disappears even with water. Purple will disappear in about 2-14 days. It disappears naturally and quickly, so it is convenient for marking that you want to disappear quickly. Twin type with broad and fine core. It is convenient to use as a line draw and fine lead for pointing. ★ Please read the instructions on the bag and test it with a cloth before using.