Opus 88 Koloro Review: The Taiwanese Factory That Revived the Japanese Eyedropper
Opus 88 of Taipei, Taiwan, is a name that spread through the fountain pen world almost overnight. Its Koloro pairs an ebonite-and-clear-acrylic body with a reservoir that holds more than 2 ml of ink. As an eyedropper priced just under 100 dollars, it has become a fixture of overseas reviews. This article digs into how it works and where it came from.
The "88" is the founding year
Opus 88 was started in Taipei in 1988 by its founder, Michael Hsu; the 88 in the name refers to that year. For a long time, though, it had no brand of its own. It worked as an OEM/ODM factory, making parts and finished pens for other makers' luxury lines. According to the American blog The Gentleman Stationer, pens under the company's own name only went on sale in earnest in the autumn of 2017. After roughly thirty years backstage, the factory stepped into the light.
What the valve in the blind cap really is
In an eyedropper the barrel itself is the ink tank. The design is simple, but the air inside expands with changes in temperature and pressure, and ink has always tended to leak from the nib. The Koloro builds a screw-down valve into the blind cap. Closed, a rubber gasket and an ebonite piston seal the section off from the tank; to write, you loosen the blind cap a few turns and let the ink through. That is why it rarely leaks on a plane.
Opus 88 did not invent this. According to the reviewer Inked Happiness, the British maker Onoto devised it in the early 1900s, and Japanese makers adopted it in the decades that followed. Abroad it is called the "Japanese eyedropper," and in recent years it was found only in expensive urushi pens such as those by Danitrio. Opus 88's achievement was to put it back into a resin pen costing a hundred dollars.
Inside the Koloro
| Item | Detail |
|---|---|
| Materials | Ebonite cap and blind cap, acrylic barrel |
| Ink capacity | Over 2 ml (importer's figure) |
| Nib | Stainless steel JoWo #5, made in Germany |
| Weight | About 25 g capped, about 15 g uncapped |
| Length | About 140 mm capped |
The nib is a screw-in unit, so any JoWo #5-compatible unit can be swapped in. Several reviews agree that its light weight makes long writing sessions comfortable.
At a price point of around 100 dollars, Opus 88 has come to be mentioned alongside TWSBI as one of Taiwan's representative brands. Dealers in Japan are still few, but PencilDB lists the Koloro in seven colours.
Sources: The Gentleman Stationer, "Pen Review: Opus 88 Koloro Demonstrators" (2018); The Pen Addict, "Opus 88 Koloro Fountain Pen Review" (2021); The Well-Appointed Desk, "Opus 88 Koloro Blue Blue" (2018); Inked Happiness, "Opus 88 Picnic" and "Unboxing the Opus 88 Fantasia"