Fudenosuke Colors Brush Pens come with a hard but flexible brush tip allowing easy transition from thick to thin lines by changing pen pressure. The water-based pigment ink provides rich vibrant colors that won't bleed through most papers. They are great for beginner brush calligraphy, hand lettering, illustration or whatever artistic or writing use you can think of. For best results use a smooth, non-textured paper. Non-refillable.