TWSBI Diamond Mini Clear Fountain Pen
The TWSBI Diamond Mini Clear is a piston filler in pocket format – completely disassembled, entirely transparent and equipped with a flexible steel nib that responds to pressure changes. The characteristic feature is the faceted piston: it not only gives the pen its name, but makes the ink level visible from every side. Grip section and cap made of clear plastic enhance this effect and allow you to monitor the ink level while writing.
Highlights
- Faceted transparent piston: The diamond-cut piston is not just a design detail – thanks to the completely transparent housing, the fill level can be read at a glance, even on the go.
- Piston system without cartridges: The pen is filled directly from an ink bottle. The piston mechanism reservoir holds significantly more ink than a standard cartridge – less refilling, more writing.
- Completely disassembled: All components can be separated without special tools. This allows thorough cleaning when changing inks – particularly important with heavily pigmented or iron gall-containing inks.
- Flexible steel nib: The nib responds to pressure variations with measurable line width changes. Not flex in the sense of a vintage flex nib, but noticeably softer than a rigid everyday nib – interesting for anyone who wants to work with ink dynamics.
- Pocket format with posting function: Closed 112 mm, with cap posted 139 mm – compact enough for jacket pocket or notebook case, but comfortable in hand with posted cap.
- Available nib sizes: EF, F, M, B and 1.1 mm broad nib – from precise fine lines to calligraphically usable width.
Application & Tips
- Ink selection: Watery, thin-flowing inks flow particularly evenly through the flexible steel nib. With heavily shimmering or particle-rich inks (shimmer), more frequent rinsing is recommended – this is easy thanks to the disassembled design.
- F nib size for everyday use: This variant (TW078.F) is suitable for medium-fine handwriting on smooth, calendered paper as well as standard copy paper. TWSBI nibs tend to be somewhat more generous than Japanese equivalents – if you prefer a fine line, you can also consider EF.
- 1.1 mm broad nib for calligraphy: The 1.1 mm variant (TW078.11) produces visible line width variations on upstroke and downstroke and is suitable for italic scripts and calligraphic everyday writing.
- Cleaning when changing inks: Simply rinse the piston several times with lukewarm water, disassemble completely if needed. The piston mechanism reservoir empties completely – no ink residue that would discolor the next color.
- Posting note: With the cap posted at the end of the barrel, the pen extends to 139 mm – a pleasant counterbalance when writing for people with larger hands.
For Pen Enthusiasts
The Diamond Mini shares its basic construction with the larger Diamond series, but is optimized for the piston system in miniature format. The disassembly follows TWSBI's philosophy of maintenance-friendly writing instruments: piston seal, piston rod and nib assembly are all separately replaceable, spare parts are offered by TWSBI long-term. The steel nib is not archival – for archival documents, a document-safe pigment-based ink is recommended. TWSBI pens are manufactured and assembled in Taiwan.
Technical Data
| Model: | TWSBI Diamond Mini Clear |
| Available nib sizes: | EF, F, M, B, 1.1 (broad nib) |
| Nib material: | Steel |
| Housing material: | Plastic, transparent |
| Ink reservoir: | Piston mechanism (no cartridge compatibility) |
| Length closed: | 112 mm |
| Length without cap: | 102 mm |
| Length with posted cap: | 139 mm |
| Maximum diameter: | 14.6 mm |
| Origin: | Taiwan |
| Scope of delivery: | Pen without ink |
