# TWSBI Eco Fountain Pen - Slate Blue with Onyx

## A muted blue Eco with Onyx accents

The TWSBI Eco Slate Blue is a limited edition piston filling fountain pen in a muted blue-grey resin. Depending on lighting, it shifts between a cooler blue and a more neutral grey tone. It is finished with black Onyx plated trim and uses the standard Eco piston filling system.

## What sets it apart

-   Muted slate blue resin which changes in different lighting
-   Black Onyx plated trim for contrast
-   High capacity piston filling system
-   Reliable steel nib with consistent flow
-   Transparent barrel for ink visibility

### Feel in the hand

The Slate Blue Eco has a restrained visual tone, with a darker blue-grey body and black trim that reduces contrast. It feels consistent and practical in use, and suits longer writing sessions where distraction-free design matters.

### Who it’s for

-   Writers who prefer muted, neutral colour palettes
-   People building a consistent daily writing routine
-   Users who want reliability without visual distraction
-   Professionals who prefer understated stationery
-   Anyone who wants a practical demonstrator with darker accents

### Not for

-   Users who prefer bright or highly saturated colours
-   People wanting pocket sized or compact pens
-   Those seeking cartridge or converter simplicity
-   Writers looking for decorative or highly expressive designs

### Practical tips

-   Apply silicone grease only if the piston becomes stiff during use. Tools are included in the box.

### FAQs

**Is this good for beginners?**  
Yes, it's widely considered one of the best entry points because of its reliability and value

**What’s different about the onyx nib?  
**The Onyx trim is primarily aesthetic and changes the visual contrast of the pen.

**Does it come with ink?**  
No, this is designed for bottled ink use. It is designed for bottled fountain pen inks.

**Can I take it apart?**  
Yes, TWSBI includes tools for maintenance, though it’s not needed often

### What’s included

-   TWSBI Eco Fountain Pen Slate Blue with Onyx
-   Wrench
-   Silicone grease
-   Simple gift box
-   [Free nib tuning](https://www.larrypost.com.au/blogs/blogs/smooth-writing-with-fountain-pens?_pos=2&_sid=a2392eaaf&_ss=r) from LarryPOST

### Ink pairing suggestions

-   Blue-black inks to match the slate tone
-   Dark blue inks for a consistent look
-   Brown inks for contrast against the cool body
-   Grey inks for a muted, low contrast palette

### Build your practice

-   [Eco plated variants](https://www.larrypost.com.au/collections/larrypost-brands-twsbi?filter.p.m.magento.brand_series=TWSBI+Eco&filter.v.price.gte=100&filter.v.price.lte=) work well as a consistent writing system
-   A simple [pen wrap](https://www.larrypost.com.au/collections/larrypost-brands-pilot-pen?filter.p.product_type=Pen+Wrap&filter.p.product_type=Pen+Roll+-+6+Pen) helps organise multiple pens  
    
-   [Midori MD](https://www.larrypost.com.au/collections/larrypost-brands-midori) notebooks offer smooth paper and a visually soft creme paper

### Specifications

-   **Brand:** TWSBI
-   **Brand series:** Eco
-   **Launch:** March 2025
-   **Origin:** Taiwan
-   **Nib:** Black Stainless steel
-   **Nib sizes:** EF, F, M, B, 1.1mm stub
-   **Filling system:** Piston filler (1.8mL)
-   **Body:** Transparent polycarbonate
-   **Cap:** Twist
-   **Diametre:** approx. 13mm
-   **Length:** approx. 139mm (capped)
-   **Weight**: approx. 21g (capped)
-   **Comparable size:** Lamy Safari, Pilot Metropolitan

A slate blue Eco with a restrained, practical finish.

## Details

- **Price:** 109.95 AUD
- **Vendor:** TWSBI
- **Type:** Fountain Pen
- **Tags:** Category_LarryPOST/Brands/TWSBI, Category_LarryPOST/Brands/TWSBI/Fountain Pen, Category_LarryPOST/Brands/TWSBI/Latest, Category_LarryPOST/Brands/TWSBI/TWSBI Eco, Category_LarryPOST/Brands/TWSBI/TWSBI Plated Editions, Category_LarryPOST/Education/2024 Fountain Day, Category_LarryPOST/Must Haves, Category_LarryPOST/New, Category_LarryPOST/New Products, Category_LarryPOST/Pens, Category_LarryPOST/Pens/Fountain Pen, Category_LarryPOST/Trending

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Extra Fine | 109.95 AUD | In stock |
| Fine | 109.95 AUD | In stock |
| Medium | 109.95 AUD | In stock |
| Broad | 109.95 AUD | In stock |
| 1.1mm | 109.95 AUD | In stock |

## Images

- TWSBI Eco Fountain Pen - Slate Blue with Onyx
- TWSBI Eco Fountain Pen - Slate Blue with Onyx
- TWSBI Eco Fountain Pen - Slate Blue with Onyx
- TWSBI Eco Fountain Pen - Slate Blue with Onyx
- TWSBI Eco Fountain Pen - Slate Blue with Onyx

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> Source: [LarryPOST](https://www.larrypost.com.au/products/twsbi-eco-fountain-pen-slate-blue-with-onyx-extra-fine-nib)
> Updated: 2026-06-15