These incredible self-outlined markers write in vivid metallic silver surrounded by colored borders. Unique technology produces outlines for you automatically to create a beautiful dual-color effect. Double Line Pen is the quality of top artists -- Waterproof, Smooth, Durable. Its ink adhesion, Color is bright and clear, Nice lines and easy to write, Very unique double line watercolor pens, Outliner Markers WIDE USE: Our outline pens can be used in writing a greeting card, scribbling, poster making, drawing and highlighting. Besides, they are also suitable for kids or adults DIY craft projects. Great for arts, school projects and more markers for coloring, Gift cards, Greeting cards, Christmas cards, Paintings, Photo album etc. Also suitable for almost any surface, such as metal, pottery, wood, rubber, glass, plastic, stone, etc. Both beginners and professionals can better release your creativity! DURABLE DESIGN & EASY TO USE: With the cap on, shake the marker well to mix the ink. Take off the cap and gently press down the tip on the surface a few times to pump the ink until it starts to flow. For best results, re-cap the markers immediately after use and store horizontally. 100% SAFETY NON-TOXIC: Made with specially formulated, xylene-free opaque ink, these metallic marker pens provide nice coverage. environmental friendly and safe for children. Our metalic pens are non-toxic, odorless, acid free, and environmentally-friendly. The water-based ink is chemically stable and fade resistant. Our ink lends itself to a smooth application that dries quickly. -Usage Instructions: -1: Shake the barrel with tip upward every time before use -2: Ink come out after 3 times continuous press tip on paper -3: Please recap immediately after use to avoid volatilization -4: Suggest to write on paper with 80gsm above, otherwise slight strike through will happen. -5: Ink is suitable to use on light color cardboard papers