Eboya Natsume Kuroi Black Large Fountain Pen
Eboya, the last factory in Japan dedicated to ebonite production. Each piece reflects a commitment to traditional craftsmanship and continuous innovation. The use of ebonite—one of the first polymers ever discovered—gives this pen a unique aesthetic: ebonite is produced by vulcanizing pure rubber with sulfur (between 25% and 50%), and its name comes from ebony, which it began to replace in certain applications thanks to its durability and natural shine. Engraved on the barrel, as on all pieces from the brand, is Eboya Made in Tokyo, a mark of its origin and excellence.
Concept and design
The Natsume model takes its name from the traditional lacquered container used in Japanese tea ceremonies to store fine matcha (usucha). Its shape is reminiscent of the jujube fruit, also called natsume (棗) in Japanese. These containers, usually made of lacquered wood, were first recorded in tea ceremony archives in 1562 and 1564, mentioned by renowned tea masters Imai Sokyu and Tsuda Sotatsu. From the Tenshō era onwards, the natsume gained great popularity among followers of tea master Sen no Rikyū, replacing other lacquered containers such as yakki, satsu or kinrin-ji[1][2]. The design of this pen, with its smooth and continuous lines, evokes the silhouette of a classic natsume, conveying balance and understated elegance.
Functionality and filling system
Equipped with a finely tuned 14K gold nib, the Natsume Kuroi Black Large delivers a smooth, precise, and well-balanced writing experience. It features a cartridge or converter filling system, compatible with international brands such as Pelikan or Rotring (not compatible with Montblanc, Waterman, or Caran d’Ache). Each barrel is hand-turned and polished in Tokyo by the artisans of Nikko Ebonite Manufacturing. The perfect assembly of all its parts, combined with the deep black ebonite, results in a pen of great beauty and quality.
Package contents
• Eboya Natsume Kuroi Black Large Fountain Pen
• Standard international converter
• Ink cartridge (1 piece)
• Paulownia wood box (Eboya replaces the standard cardboard box with this exclusive case for inktraveler)
• Warranty
(Photographs are for reference only and may differ slightly from the final product.)
Technical specifications
- Body material: ebonite
- Color: polished black (Kuroi)
- Closed length: 150 mm
- Uncapped length: 135 mm
- Body diameter: 17 mm
- Cap diameter: 18.5 mm
- Weight: approx. 28 g
- Nib: 14K gold
- Filling system: international cartridge/converter
- Made in Tokyo, Japan
Care and maintenance
Avoid direct sunlight or humidity, and store in a dark place. Occasional cleaning with a soft cloth is enough to maintain its beauty.
Brand history and philosophy
Eboya is the flagship brand of Nikko Ebonite Manufacturing, founded in 1952 and recognized as the last Japanese manufacturer specializing in ebonite. For decades, it has supplied this material to major writing instrument brands such as Sailor and Pilot. In 2009, it launched its own line of fountain pens, combining technical expertise with Japanese aesthetic sensitivity. Until 2016, production was led by master turner Noritoshi Kanesaki, a disciple of the legendary nibmeister Kubo Kohei, bringing a unique artisanal legacy. Today, Eboya continues to create durable, comfortable writing instruments with an unmistakable finish.
"A jewel that unites the Japanese tea tradition with writing excellence."
