Sakura Pigma Brush Pen have a special flexible brush nib that allows maximum creativity. Create fine lines to broad strokes merely by the amount of pressure applied to the nib. Can be used directly on rubber stamps to create permanent images for special keepsake projects. The ink is quick drying, will not bleed through most fine paper, and suitable for archival applications. For watercolor, calligraphy, designers and craft projects. Water-based, fade resistant and ph neutral. Black.