The Sign Pen Twin Brush is a water-based dye ink pen with broad brush tip on one end and fine brush tip on the other. The richly saturated colors are fully blendable with water and other sign pen brush colors. Wear-resistant, pressure-sensitive and flexible tip can be diluted with water to get a full range of values. Great for feathering, cross hatching, outlining, hand lettering, calligraphy and detailed line work. It will not dry out if left uncapped and can be cleaned with a paper towel.