# TWSBI Diamond Mini Fountain Pen - Black / Clear

## A more grounded Diamond Mini

The TWSBI Diamond Mini Black takes the transparent mechanical appeal of the Diamond series and frames it with black accents for a more focused, understated look. The clear barrel keeps the ink and piston system visible, while the black cap and grip reduce visual noise and give the pen a more controlled presence.

Built around TWSBI’s reliable piston filling system and fitted with a smooth stainless steel nib, this is a compact fountain pen that still feels complete in the hand.

## What sets it apart

-   Compact piston filler with high ink capacity for its size
-   Black accents create a sharper, more restrained aesthetic  
    
-   Transparent barrel showcases ink colour and movement
-   Posts securely to become a comfortable full length writer
-   Shares the reliable stainless steel nib from Eco

### Feel in the hand

The Diamond Mini Black feels more deliberate than the brighter Diamond variants. The black trim grounds the demonstrator body and shifts the pen toward a more practical, everyday tool feel.

Unposted it stays compact and portable. Posted, it becomes balanced enough for longer writing sessions without feeling oversized.

### Who it’s for

-   Writers wanting a compact pen without sacrificing capacity
-   Users with smaller hands who find full size pens oversized
-   People who prefer black trim over silver or coloured accents  
    
-   Travellers and everyday carry users
-   Anyone building a cleaner, more minimal writing setup
    

### Not for

-   Users who prefer large, heavier pens
-   Writers wanting cartridge/converter convenience
-   People who dislike posting smaller pens
-   Anyone wanting a completely maintenance free writing system

### Practical tips

-   The Diamond Mini is designed to post securely by threading onto the back of the barrel. Most users will prefer writing with it posted for full length balance.

### FAQs

**Is this beginner-friendly?**  
Yes. The piston system is straightforward to use and the pen box includes filling instructions.

**How much ink does it hold?**  
The chamber holds approximately 1.3mL of ink, which is still significantly more than most converter pens despite the smaller body.

**How does it compare to the Diamond 580?**  
The Mini is shorter and more portable, with slightly lower capacity. Posted, it becomes close to a full size writer. The 580 feels larger in the hand and holds more ink.

**Does the cap post securely?**  
Yes. The cap threads onto the back of the pen for a very stable posted writing experience.

**Can you change nibs?**  
Yes. The nib unit is removable and replaceable.

**Does it come with ink?**  
No. Bottled fountain pen ink is required.

**Is it fragile?**  
Not with normal use. Avoid over tightening the cap and minimise unnecessary disassembly.

**How do you clean it?**  
Routine cleaning only requires flushing water through the nib and barrel. Full disassembly is only needed occasionally for piston lubrication.

### What’s included

-   TWSBI Diamond Mini Black / Clear Fountain Pen
-   Wrench
-   Silicone grease
-   Presentation box
-   Instruction leaflet
-   [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

-   Black and blue-black inks for a monochrome feel
-   Deep teals and dark greens for subtle contrast
-   Iron gall inks for a more archival, traditional character

### Build your practice

-   Use with the TWSBI Diamond Ink Well for cleaner filling
-   Replacement Diamond Mini nibs for exploring line widths
-   De Atramentis Document inks for permanence  
    

### Specifications

-   **Brand:** TWSBI
-   **Brand series**: Diamond Mini
-   **Origin:** Taiwan
-   **Nib:** Stainless steel
-   **Nib sizes:** EF, F, M, B, 1.1 stub
-   **Filling system**: Piston filler (approx. 1.3mL)
-   **Body:** Transparent polycarbonate
-   **Trim:** Stainless steel
-   **Cap:** Twist
-   **Grip:** Approx. 9mm
-   **Diameter:** approx. 12mm
-   **Length:** approx. 117mm (capped)
-   **Length:** approx. 138mm (posted)
-   **Weight:** Approx. 20g
-   **Comparable size:** Kaweco Sport, Pilot Prera

A compact demonstrator that balances portability with a more controlled, understated writing experience.

## Details

- **Price:** 109.95 AUD
- **Vendor:** TWSBI
- **Type:** Fountain Pen
- **Tags:** Category_LarryPOST, Category_LarryPOST/Brands/TWSBI, Category_LarryPOST/Brands/TWSBI/Fountain Pen, Category_LarryPOST/Brands/TWSBI/TWSBI Diamond Mini, Category_LarryPOST/Pens, Category_LarryPOST/Pens/Fountain Pen

## 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 Stub | 109.95 AUD | In stock |

## Images

- TWSBI Diamond Mini Classic Fountain Pen - Black / Clear
- TWSBI Diamond Mini Fountain Pen - Black / Clear
- TWSBI Diamond Mini Fountain Pen - Black / Clear
- TWSBI Diamond Mini Fountain Pen - Black / Clear
- TWSBI Diamond Mini Fountain Pen - Black / Clear
- TWSBI Diamond Mini Fountain Pen - Black / Clear

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> Source: [LarryPOST](https://www.larrypost.com.au/products/twsbi-diamond-mini-fountain-pen-black-clear)
> Updated: 2026-08-02