Pentel Brush Tip Sign Pens achieve a variety of techniques, including feathering, cross hatching, outlining, calligraphy and detailed line work. The pens have a flexible tip that is wear-resistant and pressure-sensitive, meaning you can regulate your line depending on the amount of pressure you apply to the paper. Dilute the tip with water to get a full range of values. They will not dry out if left uncapped and can be cleaned with a paper towel. ACMI Certified.