After painting with the water pen the whole color changes immediately about 8-10 minutes later the color will automatically disappear. It can be used repeatedly very environmentally friendly. Textured fabrics and bright colors help to develop children's sensory awareness. Manufacturered by Novobey. It's lightweight and conventient to carry with. Suitable for 10 months to 3 years old children. A fascinating & easy-to-learn water painting graffiti book cards for kids. Great gift for kids on birthday children's day or Christmas day. The dye of the pen is water non-toxic easy to clean. Dont afraid that the baby or your house would get dirty.