TWSBI Piston Filler ECO Irish Green with Onyx EF
The TWSBI ECO Irish Green with Onyx is a piston filler from Taiwan with a transparent acrylic barrel and rich green cap and piston knob. Onyx-black nib, clip and trim ring create a striking contrast to the clear shaft – through which the ink level is visible at all times. The integrated piston system holds approx. 1.7 ml of ink, which is significantly more than a standard converter offers, making the ECO a reliable companion for intensive writing days.
Highlights
- Piston filling system with approx. 1.7 ml capacity: Filled directly from the ink bottle – no converter, no cartridges. The piston is operated by turning the end knob and cleanly draws the ink into the shaft.
- Transparent demonstrator barrel: Acrylic glass reveals fill level and ink colour. Coloured inks, shimmer inks and inks with shimmer pigments unfold their full effect here.
- Irish Green and Onyx: Cap, piston knob and inner cap in deep emerald green; nib, clip and trim band in matte onyx black – polished steel nib with TWSBI engraving.
- Hexagonal cap: The faceted cap sits securely in the hand and stays on the desk without rolling away.
- Inner seal and O-ring: Cap with inner cap and rubber O-ring on the thread seals the barrel airtight – the nib does not dry out even during longer writing breaks.
- Completely disassemblable: Included wrench and silicone grease allow cleaning, maintenance and re-lubrication of the piston at home – without a workshop.
- Available in five nib sizes: EF, F, M, B and broad nib 1.1 – Western nib size standards, manufactured in Germany.
Application & Tips
- Filling: Turn the end knob counterclockwise until the piston is fully extended, dip the nib deep into the ink bottle, turn the knob back clockwise. For maximum filling: repeat the process two to three times, hold the filler vertically and expel air bubbles by gentle pressure.
- EF and F: Precise, narrow line widths for narrow-lined notebooks, bullet journaling and small handwriting. On smooth, fade-resistant paper, the EF nib produces hairline-fine strokes.
- M and B: Rich, fluid writing flow – ideal for expressive handwriting, journals and flowing text, where inks with shading and shimmer particularly shine.
- Broad nib 1.1: Light edge width with stroke-to-hairline contrast; suitable for brush lettering basics, simple calligraphy and expressive headlines.
- Cleaning: Regular rinsing with clear water recommended – especially when changing inks. The cap can be completely removed and rinsed separately. Avoid pigmented inks and drawing inks; pure dye-based fountain pen inks extend the lifespan of the piston seal ring.
- Maintenance: Re-lubricate the piston once a year with the included silicone grease – to do this, completely disassemble the filler and apply a thin coat of grease to the piston rod.
For Fountain Pen Enthusiasts
The ECO's nibs are manufactured in Germany and conform to Western nib size standards. The Onyx version combines the clear acrylic barrel with a black-coated steel nib, whose matte finish differs tactilely and visually from polished standard nibs. The piston system is identical to that of the TWSBI Diamond 580 series – anyone familiar with both will recognise the identical filling feel. Due to its complete disassemblability, the ECO is also serviceable for inks with shimmer pigments: after using such inks, the piston chamber and feed can be thoroughly cleaned without risking residue.
Technical Data
| Model / Series: | TWSBI ECO Irish Green with Onyx |
| Colour: | Irish Green (cap, piston knob) / Onyx Black (nib, clip, trim ring) |
| Barrel material: | Transparent acrylic (demonstrator barrel) |
| Filling system: | Integrated piston mechanism |
| Ink capacity: | approx. 1.7 ml |
| Length (cap on): | approx. 139 mm |
| Length (cap posted): | approx. 168 mm |
| Nib: | Onyx-black steel nib, manufactured in Germany, Western standard sizes |
| Available nib sizes: | EF, F, M, B, broad nib 1.1 |
| Origin: | Taiwan |
| Scope of delivery: | Filler, wrench, silicone grease, presentation box |