These pens are durable watercolor paint brushes. They give a sensitive response to delicate lines or pools of colors. Easy to clean. You just wash it under water after you use it. Control the ink or water flow with just a squeeze of the barrel. Features - Material: Plastic. - Durable nylon hair brush tips can hold a point fairly well, so it will not spray or smear. - You can draw the finest line or color large lines, blend colors and create new shades. - Great for solid colors or powdered pigment, used with watercolor crayons, water-soluble pencils, water-soluble pigments, inks. - Easy to control the flow of water and allow better flow control. - No messy watercolor brush pen gives you peace of mind while painting. No more dealing with messy water bowls and spilled water