TWSBI Eco Fountain Pen - Rootbeer with Bronze Trim and NibA warm amber Eco with a cola finish The TWSBI Eco Rootbeer with Bronze is a piston filling fountain pen in a warm amber brown transparent resin, with cola like undertones. It uses the standard Eco piston system, giving it high ink capacity and full visibility of ink inside the barrel. The bronze trim adds contrast to the warm body colour. What sets it apart Warm rootbeer inspired amber brown transparent resin Bronze coloured trim for contrast against