TWSBI Eco Fountain Pen - Carrara with Onyx Trim and NibA quieter, stone inspired take on the Eco The TWSBI Eco Carrara with Onyx trim takes inspiration from the veined texture of Carrara marble, translated into a mixed resin finish of greys, whites, and subtle blue tones. Each pen varies slightly due to the pour process, so no two are exactly the same. Onyx black trim keeps the overall look grounded, while the Eco piston system delivers the same high ink capacity the range is known for. What sets it apart