The versatility of the Color Brush makes it easy to use between line and wash. The water-based dye ink dries quickly and produces rich intense colors. The durable nylon brush tip can flood wide strokes with solid color and then give a light touch to delicate lines. The refill barrels are easy to replace, and the reverse thread stops any leakage. Also included in this pack is the Pentel Arts Aquash Water Brush which can be filled with water and used to blend powdered pigments, water colors, pencils, pastels and more.