1Water-based pigment ink, waterproof, light-resistant, good coverage, low odor, can write on a variety of surfaces, such as paper, canva, glass, plastic, cloth, wood, metal and so on. 2There are two steel balls on each pen to make the ink shake more evenly. 3The transparent pen can clearly see the ink inside, and always know the left of the ink. 4The color of the pen and ink is the same, so you can easily pick the color you like. 5Environmentally friendly, non-toxic, fast drying, waterproof, opaque, and resistant to sun drying.