Ecoline Duotip pens contain concentrated, transparent watercolour paint. These brilliant watercolours in combination with the two different nibs give you the freedom to make fine or broad lines and to colour larger areas. The dye-based Duotips work perfectly in combination with the Ecoline Brush Pen and Ecoline bottles and offer you a wide range of options in line weights, styles and colour variations. Mix with water for beautiful watercolour effects and smooth colour transitions.