【Double Line Outline Pens】Double line outline marker pens made with xylene-free opaque ink, which is safe,non-toxic,tasteless,acid-free and environmentally friendly.These metallic outline markers are written in vivid metallic silver with a colorful border around them. Unique technology automatically generates contours for you to create beautiful two-color effects and also the lines you write will be very smooth. The ink adhesion is also very good. 【12 Shiny Colors】Available in 12 different colors containing shiny ink, which yield a vivid color and add a sparkle luster. Also suitable for almost any surface, such as metal, pottery, wood, rubber, glass, plastic, stone, etc. With these outline marker, double lines will appear on light-colored paper, silver lines will appear on dark paper, and single-color lines will appear on smooth surfaces (such as glass). 【Durable 1mm Tip】Double line pen specially designed with a wear-resistant and pressure-resistant chisel tip, that helps to achieve fluid and smooth clear writing effortlessly across the page. The pigment ink is waterproof, chemically stable and UV resistant. Our ink lends itself to a smooth application that dries quickly. 【Easy to Use】With the cap on, shake the double line marker pens 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. Suggest to write on heavy paper, otherwise the ink will bleed through the thin paper. 【Wide Application】Our outline pen has nice lines and easy to write, can be used in writing crafts, stamping, gift cards, greeting cards, Christmas cards, DIY craft projects, personality posters, paintings, photo album etc.NOTICE: In order to increase the service life of the pen, it is recommended to follow the steps in the instruction before every use, cover the cap after use and place the end of the cap up.