TWSBI Eco Fountain Pen Cosmos Blue with Onyx

The TWSBI Eco Cosmos Blue with Onyx Fountain Pen perfectly combines modern design, high performance, and exceptional value. Its vibrant Cosmos Blue cap paired with elegant Onyx black trim creates a bold and sophisticated aesthetic, ideal for both everyday writing and serious collectors.

Built on TWSBI’s beloved ECO platform, this pen features a piston-filling mechanism that delivers a generous ink capacity, eliminating the need for cartridges or converters. The transparent demonstrator barrel allows you to see your ink level and piston action, adding to the pen’s visual charm.

Each nib is precision-crafted stainless steel, known for smooth, consistent ink flow and effortless writing performance. Available in multiple nib sizes, the ECO Cosmos Blue with Onyx suits any writing style — from fine daily notes to expressive journaling. The pen’s balanced weight, ergonomic grip, and durable resin construction ensure comfortable long writing sessions.

Like all TWSBI pens, it’s fully serviceable — you can easily disassemble and maintain it using the included wrench and silicone grease, ensuring long-term reliability.

Whether you’re a beginner exploring piston fillers or a seasoned writer looking for a stylish daily companion, the TWSBI Eco Cosmos Blue with Onyx stands out for its quality and design excellence. Its striking colour combination makes it one of the most visually captivating editions in the ECO line.

For fountain pen enthusiasts in India, especially in Delhi NCR, this elegant model is available at Pen Planet — a trusted retailer for premium writing instruments and exclusive TWSBI releases. You can also follow @pen__planet on Instagram for the latest arrivals, in-hand photos, and pen-inspiration posts.

The TWSBI Eco Cosmos Blue with Onyx is more than just a pen — it’s an expression of creativity, craftsmanship, and everyday elegance, available now through Pen Planet India.