The Kuretake Bimoji Fude Pen is a twist on a traditional Japanese brush. Black, water-based pigment ink is, light-fast, permanent and water-proof when dry. Plastic bodies mimic lightweight bamboo brushes. Available in 4 sizes; extra fine and fine pens feature a hard tip, medium size has a firm tip, large has a flexible tip ideal for large areas. The medium brush tip is most like a brush.