Dual brush pens have a versatile, flexible nylon fiber brush tip on one end and a fine tip on the other end. The resilient nylon brush retains its point. Water-based, non-bleeding ink is blendable. Set includes 10 colors: cool gray 7, green, jet blue, lamp black, light orange, pink rose, purple sage, rhodamine red, royal purple and turquoise. Acid-free. AP Seal, non-toxic.