TWSBI Piston Fountain Pen Diamond 580 Clear
The TWSBI Diamond 580 Clear is a fully disassemblable piston filler made of transparent plastic – a classic demonstrator concept where ink color and fill level are always visible. The faceted barrel catches the light and gives the pen its characteristic diamond character. The flexible steel nib responds to pressure changes with slight line width variation; the integrated piston system holds approximately 1.95 ml of ink directly from the bottle – no converter, no cartridge.
Special Features
- High-capacity piston filling system: Up to approximately 1.95 ml of ink directly from the bottle – this means significantly longer writing sessions without refilling, ideal for intensive writing or extended calligraphy practice.
- Transparent plastic barrel: Grip, cap, and barrel are completely clear – the ink inside is always visible, color changes and remaining quantity can be seen at a glance.
- Faceted barrel: The cross-set facets of the barrel give the pen a gemstone-like appearance; at the same time, the surface texture prevents the pen from rolling off the desk.
- Steel nib with slight flexibility: The polished steel nib responds to increased pressure with slight line width variation – for a livelier script without the full flex of a flex nib.
- Threaded cap with inner sealing ring: The cap screws on and closes with a rubber sealing ring – the nib remains permanently moist, writing starts without hard starts or skipping.
- Fully disassemblable: All parts can be separated with the included wrench; this allows thorough cleaning when changing ink and maintenance of the piston mechanism with the included silicone oil.
- Not cartridge compatible: Exclusively bottled ink – the pen comes without ink and without cartridge adapters.
Use & Tips
- Choose bottled ink: Aqueous standard fountain pen inks flow reliably in the Diamond 580; heavily shading or iron gall-containing inks are also possible. Satin or pigmented inks (e.g., nano inks) only according to manufacturer specifications – the piston seal can be sensitive to deposits.
- Nib size based on script size and writing tool: EF and F for small, precise writing on smooth, calendered paper; M for relaxed everyday writing; B for expressive handwriting or headings. The 1.1 mm broad nib creates a soft italic line with visible horizontal-vertical contrast – ideal for lettering and beginner calligraphy.
- Optimal filling: Turn the piston completely downward before dipping, insert nib deep into the bottle, pull up slowly. Then hold the nib upward and expel small air bubbles by briefly pressing the piston – this ensures you use the full capacity.
- Cleaning when changing ink: Rinse the piston multiple times with lukewarm water. For stubborn residue, disassemble the pen with the included wrench; after drying, lightly lubricate the piston mechanism with the included silicone oil.
- Paper recommendation: On smooth, ink-resistant paper, the steel nib shows its best script and minimal feathering; with the 1.1 mm broad nib, particularly recommended so that the writing stands cleanly.
For Fountain Pen Enthusiasts
The steel nib of the Diamond 580 is manufactured by TWSBI in Germany and calibrated to Western standards – the sizes are therefore broader than Japanese equivalents. The piston mechanism is a classic screw piston: the rotational movement at the knob end moves the rubber damper axially through the barrel. The silicone oil in the package is exclusively intended for the piston seal; do not use mineral oil-based lubricants as these can damage plastic parts. The cap can be mounted on the grip end, extending the pen to 176 mm – due to the piston knob then pointing upward, unwanted piston movement can occur when capping; a note for those who consistently post the cap.
Technical Data
| Model: | TWSBI Diamond 580 Clear |
| Material: | Transparent plastic |
| Nib material: | Steel |
| Available nib sizes: | EF, F, M, B, 1.1 |
| Ink reservoir: | Piston mechanism (approx. 1.95 ml) |
| Length closed: | 142 mm |
| Length without cap: | 129 mm |
| Length with cap on: | 176 mm |
| Maximum diameter: | 14.9 mm |
| Origin: | Taiwan |
| Included: | Pen, wrench, silicone oil, plastic display box, without ink |
