The ink is permanent once used on the paper, adding to the advantage of storing the painting, making calligraphy, sketching and illustration interesting and long-lasting. Some other features of Camlin’s Artist Brush Pens include the following: • Pigment Based Ink • UV Resistant • Water Proof Ink • Permanent Imprint • Acid Free • Lightfast Colours • Soft and Flexible Tip Simply allow yourself to be inspired by nature and explore your imagination on paper with your brush pens! Once you practice, you will get the hang of it!