The super rich water-based dye ink in these pens create vivid expressions for artists at all skill levels. Each tip is made from high quality polyester fiber that lets the color flow but keeps its point. Marker features fine bullet shaped tip on one side for landscape studies, gesture drawings, watercolor paintings, cartooning and portraiture. The other side has a medium bullet shaped tip for a bolder approach or to fill in large areas with color. Ink is acid-free and non-toxic and caps are ventilated for safety.