These pens are durable watercolor paint . They give a response for delicate lines or pools of colors. They are easy to clean. You just washi it under water after used. Control the ink or water flow with just a squeeze of the barrel. Blend with water or add ink to barrel for fast, easy, and fun painting. Features - - Material: PP and nylon. - Packing Size: About 19 x 2cm. - Durable watercolor paint . - Give a response for delicate lines or pools of colors. - Control the ink or water flow with just a squeeze of the barrel. - Great for solid colors or powdered pigment, use with watercolor crayons, markers, and pencils to spread and smooth colors. - The will be easy to clean after used. - Warm Tip: Dear buyer, due to lighting effect, monitor’s brightness, manual measurement and etc, there could be some slight differences in the color and size between the photo and the actual item. Sincerely hope that you can understand! Thank you! Package list: 9 brush pen