Perfectly horizontal profile of the capped TWSBI ECO Plum Onyx fountain pen centered on a pure white background. The clean, straight-on composition emphasizes the clear demonstrator barrel, the rich plum purple resin cap and blind cap, and the stealthy onyx black pocket clip and trim rings.
Top-down view of the uncapped TWSBI ECO Plum Onyx fountain pen and its detached cap arranged diagonally over subtle white acrylic display rings on a pure white background. The shot details the dark onyx-plated nib, the internal piston mechanism, and the deep plum purple resin components.
Angled product photograph of the fully capped TWSBI ECO Plum Onyx fountain pen on a pure white background. The image clearly displays the striking contrast between the rich plum purple cap and piston knob, the stealthy dark onyx-plated pocket clip, and the clear ink barrel.
Uncapped, angled view of the TWSBI ECO Plum Onyx fountain pen resting on a seamless white background. The photograph highlights the dark onyx black-plated stainless steel Jowo nib, the clear high-capacity demonstrator barrel, and the distinct deep plum purple resin piston knob.
Moody product photograph of the uncapped TWSBI ECO Plum Onyx fountain pen resting horizontally across a fresh red plum, with its matching deep purple cap standing vertically beside it. The dark background and rustic wooden surface highlight the pen's clear demonstrator barrel and stealthy dark onyx-plated nib and trim.
Top-down flat lay photograph of the uncapped TWSBI ECO Plum Onyx fountain pen and its cap resting on white marble, beautifully contrasted alongside sliced and whole fresh dark plums on a warm beige surface. The elegant composition emphasizes the rich plum purple resin and sleek onyx black accents.
Perfectly horizontal profile of the capped TWSBI ECO Plum Onyx fountain pen centered on a pure white background. The clean, straight-on composition emphasizes the clear demonstrator barrel, the rich plum purple resin cap and blind cap, and the stealthy onyx black pocket clip and trim rings.
Top-down view of the uncapped TWSBI ECO Plum Onyx fountain pen and its detached cap arranged diagonally over subtle white acrylic display rings on a pure white background. The shot details the dark onyx-plated nib, the internal piston mechanism, and the deep plum purple resin components.
Angled product photograph of the fully capped TWSBI ECO Plum Onyx fountain pen on a pure white background. The image clearly displays the striking contrast between the rich plum purple cap and piston knob, the stealthy dark onyx-plated pocket clip, and the clear ink barrel.
Uncapped, angled view of the TWSBI ECO Plum Onyx fountain pen resting on a seamless white background. The photograph highlights the dark onyx black-plated stainless steel Jowo nib, the clear high-capacity demonstrator barrel, and the distinct deep plum purple resin piston knob.
Moody product photograph of the uncapped TWSBI ECO Plum Onyx fountain pen resting horizontally across a fresh red plum, with its matching deep purple cap standing vertically beside it. The dark background and rustic wooden surface highlight the pen's clear demonstrator barrel and stealthy dark onyx-plated nib and trim.
Top-down flat lay photograph of the uncapped TWSBI ECO Plum Onyx fountain pen and its cap resting on white marble, beautifully contrasted alongside sliced and whole fresh dark plums on a warm beige surface. The elegant composition emphasizes the rich plum purple resin and sleek onyx black accents.

TWSBI ECO Piston Filler Fountain Pen - Plum Onyx

$55.00
/
Shipping calculated at checkout.
Nib Size
  • Edition: Plum Onyx — Special Edition featuring a rich, deep plum purple resin paired with sleek, stealthy onyx black plating
  • Nib: Onyx Black Steel — Precision Jowo stainless steel nib plated in dark onyx to perfectly match the trim
  • Filling Mechanism: Piston Filler — Internal piston draws ink directly into the barrel (approx. 1.76ml capacity)
  • Ink Capacity: Massive — Holds nearly 4x more ink than a standard converter
  • Body: Crystal Clear — Transparent barrel allows you to see your ink level and color at all times
  • Maintenance: Fully Serviceable — Includes wrench and silicone grease for home disassembly
  • Dimensions: 139 mm capped, 168 mm posted — Hexagonal cap prevents rolling and posts securely
  • Origin: Made in Taiwan — Precision engineered for durability

About the TWSBI ECO Piston Filler Fountain Pen – Plum Onyx

The TWSBI ECO Piston Filler Fountain Pen – Plum Onyx is a striking Special Edition that brings a bold, modern edge to the reliable ECO lineup. Elevating the standard demonstrator design, this pen features a rich, deep Plum purple cap and piston knob, beautifully contrasted by stealthy Onyx black-plated trim and a matching dark onyx-plated nib.

The ECO (short for "Economical") is celebrated for bringing high-end piston filling mechanisms to an accessible price point. The built-in piston allows you to fill the pen directly from a bottle, holding a massive 1.76ml of ink. The crystal-clear barrel not only lets you monitor your ink level at a glance but also turns your ink of choice into a vibrant visual centerpiece against the dark, moody plum and black accents.

Designed for flawless daily use, the cap features an inner seal to prevent the nib from drying out, even if left unused for extended periods. The distinct hexagonal cap prevents the pen from rolling off your desk, while the smooth, round grip section ensures a remarkably comfortable writing experience.

True to TWSBI’s philosophy of user empowerment, the pen arrives in a presentation box that includes a bespoke wrench and silicone grease, giving you the freedom to fully disassemble, clean, and lubricate the mechanism yourself—ensuring your tool lasts a lifetime.

In Stock & Ready
Every tool is personally dispatched from our hubs within 48 hours (2 business days).

Standard Tracking (Registered Airmail)

  • United States: USD 14.99 | FREE over USD 150
    [✔ Duties & Taxes: Prepaid by Us]
  • Rest of the World: USD 8.99 | FREE over USD 99
  • Fully tracked to your doorstep via national post or local courier.

Expedited Priority (FedEx/DHL)

  • United States: USD 39.99 (3–5 Business Days)
    [⚠ ~$30 Carrier Fee: Billed to Recipient*]
  • Rest of the World: USD 29.99
  • The fastest global route via premium express couriers.

Our Logistics Commitment
Orders are handled at our precision fulfillment centers in Hong Kong or Taiwan. For our US community, we absorb import tariffs on Standard Shipping to keep rates fair.

*Note: US Expedited couriers invoice recipients directly for individual customs clearance and administrative fees (typically ~USD 30).

Rates are listed in USD; our system automatically converts these to your local currency at checkout.

[View Full Shipping Policy]

This site is protected by hCaptcha and the hCaptcha Privacy Policy and Terms of Service apply.

You may also like

Recently viewed

Back to Pens