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406 products
406 products
580 has increased ink capacity, about 30% more than 530
580 has improved the smoothness of cap thread turning
580 shows you our promise on continuous product improvement on small details
Please note : ink is not included
The idea behind the TWSBI Diamond 530, 540, and 580 was to go back to basics and capture the simplicity and elegance of traditional writing instruments. In recent years, the development and modernization of writing instruments has resulted in traditional writing instruments, such as fountain pens, falling into obscurity. It was our goal to bring the past back to life by creating a traditional fountain pen that even modern day society can appreciate.
TWSBI Diamond 580, a classic fountain pen with a piston ink-filling system. By fusing the traditional mechanisms of the fountain pen with a modern industrial design, we have created an eye-catching fountain pen that is simultaneously appreciative of the past and relevant in the present. The Diamond 580 comes with a benchmark ink-filling mechanism and has all detachable parts. We felt that it was important to allow the user to disassemble and reassemble the pen and completely experience the traditional aspects of owning and using a fountain pen.
A quick no brainer guide in choosing nib sizes in an overly complicated fountain pen world:
If you write small, go with an EF
For the normal writer, F is the most popular
If you tend to lean on a bigger font, M will be perfect
B is for statements!! Sign a check in B, write a header in B, do some coloring/shading in B
Stub nibs are italic in writing style (have a special card or invitation to write?)
The Platinum #3776 Cherry Blossom Celluloid fountain pen features a delicate cherry blossom pattern set in soft pink celluloid with elegant gold trim. Rare in modern penmaking, celluloid is prized for its depth, warmth, and luminous finish, and requires months of careful curing to perfect.
Fitted with a smooth 14k gold nib, this pen uses Platinum proprietary cartridges or a converter for bottled ink. Both are included, making it ready to write right out of the box.
Specifications:
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Body Material: Celluloid
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Trim: Gold
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Nib Material: 14k Gold
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Filling Mechanism: Cartridge / Converter
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Compatible Inks: Bottled ink, Platinum proprietary cartridges
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Body Diameter: 12.0 mm (0.47 in)
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Grip Diameter: 10.0 mm
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Overall Length (Closed): 136.8 mm (5.39 in)
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Body Weight: 13 g (0.46 oz)
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Postable: Yes
The Opus 88 Demonstrator Sapphire fountain pen makes a bold impression with its sparkling, swirling acrylic resin in a rich sapphire blue. Its clean, cylindrical profile with flat ends highlights the modern demonstrator design, while a JoWo #6 steel nib finished in black PVD delivers smooth, dependable writing performance with a sleek, contemporary look.
This pen features Opus 88’s signature eyedropper filling system, offering an exceptionally large ink capacity. To fill, simply unscrew the grip section, use the included pipette to add ink, and reassemble the pen. Before writing, the rear blind cap must be loosened to open the internal valve. This shut-off valve system allows you to control ink flow—open it for extended writing sessions and close it when traveling or storing the pen—providing both convenience and peace of mind in everyday use.
Color: Blue
Trim: Gun metal
Filling System: Eyedropper
Nib: Extra Fine, Fine, Medium, Broad or Stub 1.5
Nib Material: Steel
The Opus 88 Demonstrator fountain pens pair bold, expressive colorways with a classic true eyedropper filling system. Machined from solid bar stock, each pen is equipped with a smooth-writing #6 stainless steel nib, delivering reliable performance alongside striking design.
The 2024 Special Edition features a playful, juicy color palette, blending translucent light pink resin with a rich purple grip and blind cap, accented by a deep green cap finial for contrast. Black PVD finishing on both the pocket clip and the #6 stainless steel nib adds a modern, cohesive touch. With an impressive 4 ml ink capacity, the Demonstrator includes a central shut-off rod that controls ink flow and helps prevent leaks during travel or storage. The screw-down valve securely seals the ink inside the barrel, offering added peace of mind and making it a safer, more practical option than traditional eyedropper-filled fountain pens.
Color: Pink, other
Trim: Black
Filling System: Eyedropper
Nib: Extra Fine, Fine, Medium, Broad or Stub 1.5
Nib Material: Steel
The Opus 88 Demonstrator fountain pen is a distinctive, thoughtfully engineered writing instrument designed for those who appreciate both form and function. This large, non-postable pen features a true eyedropper filling system paired with a piston-operated shut-off valve, offering exceptional ink capacity and added security. Its striking combination of frosted and clear resin creates a clean, modern aesthetic that stands out, complemented by a sleek black clip and a silver stainless steel #6 JoWo nib for smooth, reliable writing. A glass eyedropper is included for easy filling with your favorite ink.
An ebonite piston and rubber gasket seal the feed from the barrel when fully closed, helping to prevent leakage and ink burping during travel or storage. To write, simply unscrew the blind cap and slightly loosen the rear rod to open ink flow to the feed; for extended writing sessions, leaving the valve open allows you to take full advantage of the pen’s impressive ink capacity. The fully clear body lets you easily monitor ink levels and view the nib even while capped.
Note: JoWo is transitioning from the traditional scroll nib design to a simpler engraving. Current stock may include either style, and the nib received may differ from photos shown.
Color: Clear
Trim: Black
Filling System: Eyedropper
Nib: Extra Fine, Fine, Medium, Broad or Stub 1.5
Nib Material: Steel
The Opus 88 Demonstrator Mocha Mousse fountain pen is a bold and thoughtfully engineered writing instrument designed for writers who appreciate both capacity and control. This large, non-postable pen features an eyedropper filling system, offering exceptional ink capacity while minimizing leaks during travel or storage. It is fitted with a black stainless steel #6 JoWo nib for smooth, dependable performance and includes a glass eyedropper for easy filling with your favorite fountain pen ink.
Finished in a warm, café-inspired palette, the Mocha Mousse design pairs an opaque light brown cap and barrel with translucent dark brown finials, creating a visually rich yet understated look. This colorway is a limited edition for 2025, making it a distinctive addition to any collection. An ebonite piston and rubber gasket seal the ink chamber when fully closed, preventing burping and leakage. Simply unscrew the blind cap and slightly loosen the rear rod to open ink flow to the feed. For extended writing sessions, leaving the valve open allows you to fully enjoy the pen’s impressive ink capacity and uninterrupted writing experience.
Color: Brown
Trim: Gun metal
Filling System: Eyedropper
Nib: Fine, Medium, or Broad
Nib Material: Steel, black
Created by Opus 88 to celebrate the Pantone Color of the Year 2025, the Harmony Mocha Mousse offers a fresh and unexpected take on coffee-inspired fountain pens. A translucent purple barrel sets it apart, complemented by soft cream accents on the grip, cap ends, and finial, and finished with elegant rose gold trim. The result is a distinctive yet refined design that brings something truly unique to any café-themed or curated pen collection.
The Harmony Mocha Mousse features an eyedropper filling system, allowing the barrel to be filled with ink using the included pipette. This design provides a significantly larger ink capacity than standard fountain pens, making it ideal for long, uninterrupted writing sessions.
Color: Purple, White
Trim: Rose Gold
Filling System: Eyedropper
Nib: Fine, Medium, or Broad
Nib Material: Steel
The Opus 88 Holiday Jazz fountain pen features a refined frosted clear barrel and cap, paired with sleek gunmetal accents for a modern, understated look. This large, postable pen utilizes a true eyedropper filling system combined with a piston-like shut-off valve, delivering an impressive ink capacity with added security. It is fitted with a silver stainless steel #6 JoWo nib for smooth, consistent writing and includes a glass eyedropper for easy filling with your favorite fountain pen ink.
An ebonite piston and rubber gasket seal the feed from the barrel when fully closed, helping to prevent leaks and ink burping during travel or storage. To begin writing, simply unscrew the blind cap and loosen the rear rod to open ink flow to the feed. For extended writing sessions, leaving the valve open allows you to fully enjoy the pen’s generous ink capacity. The frosted clear body also makes it easy to monitor ink levels and view the nib even while the pen is capped.
Note: JoWo is transitioning from the traditional scroll nib engraving to a simpler design. Current inventory may include either style, and the nib you receive may differ from product photos.
Color: Clear
Trim: Silver
Filling System: Eyedropper
Nib: Fine, Medium, Broad or Stub 1.5
Nib Material: Steel
