Pentel Brush Sign set Rainbow. This set contains 24 colors. The flexible fiber tip of the Pentel Brush Sign Pen allows variable line thicknesses depending on pressure. With its fine flexible nib, it is the ideal pen for sketching, illustrating, handlettering and small-scale calligraphy. Easy to handle and therefore particularly suitable for beginners. Water-based ink. Metal-framed very robust tip. Not refillable.