These refillable empty markers feature a pump action valve which allows you to control the flow of the paint. Empty markers can be filled with your color choice of Angelus Acrylic Paint mixed with Angelus 2-Thin (1:1 ratio). Most colors will require adjusting with 2-Thin in order to flow right. One end features a chiseled tip, great for creating shapes and lines and the other end features a rounded tip, perfect for small details or line work.Details:5 mm empty markers20 packs (2 markers per pack, 40 total markers)Replaceable dual-sided tipsChiseled and rounded tipsEmpty markers don't work with metallic or neon