Pentel Color Brush Pigment Gray Marker #137 Color brush markers have synthetic nylon bristles that do not deform with use. This tip will allow you to control the thickness of the line. High quality water-based pigment ink. Once the pigment ink dries completely , it becomes waterproof. It is ideal for box layering techniques or for use in conjunction with watercolors or other wet mediums. Includes a valve to control flow and prevent brush drips. Perfect for techniques calligraphy, comic drawing, illustration, etc. Color: gray Number: 137 Brand: Pentel