Eboya Houju Kuroi Black Large Fountain Pen
Eboya is the last factory dedicated to ebonite production in Japan. Each piece reflects a commitment to traditional craftsmanship and continuous innovation. Ebonite—one of the first polymers ever discovered—gives this pen a unique aesthetic: it 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 due to its durability and natural shine. The engraving Eboya Made in Tokyo on the body is a testament to its origin and excellence.
Concept and design
The Houju model takes its name from the “宝珠” (Hōju), considered to be the property of dragons and, according to tradition, able to grant gold, silver, treasures, and anything one may desire, as well as guiding one to live life as they wish, making dreams come true. This symbol, typically represented as a sphere or teardrop with a pointed tip, can be found on the roofs of Inari Shinto shrines or in the mouth or beneath the paw of Inari’s messenger, the fox, representing the power to grant wishes, purify, and protect[1][2][3]. Its design features a delicate, rounded silhouette with a standard cap-fitting system for smooth closure, complemented by a Japanese-made gold-plated clip that expresses the wish for this special piece to be cherished and appreciated for many years.
Filling system and nib
Fitted with a carefully tuned 14K gold nib, the Houju Kuroi Black Large delivers smooth, precise, and balanced writing. It uses an international standard cartridge/converter filling system, compatible with brands such as Pelikan or Rotring (not compatible with Montblanc, Waterman, or Caran d’Ache). Each body is turned and polished in Tokyo, continuing the artisanal traditions of Nikko Ebonite Manufacturing. The perfect assembly of all its parts, together with the color of its ebonite, results in a piece of great beauty and quality.
Package contents
• Eboya Houju Kuroi Black Large fountain pen
• International standard converter
• Ink cartridge (1 piece)
• Premium paulownia wood box (Eboya replaces for inktraveler the standard cardboard box with this exclusive presentation)
• Warranty
(Image credit for Houju monument: By じぶろ - Own work, CC BY-SA 3.0, link).
Technical specifications
- Body material: ebonite
- Color: polished black (Kuroi)
- Closed length: 142 mm
- Posted length: 165 mm
- Body diameter: 15 mm
- Cap diameter: 16.5 mm
- Weight: approx. 26 g
- Nib: 14K gold
- Filling system: international cartridge/converter
- Made in Tokyo, Japan
Care and preservation
It is recommended to avoid direct exposure to sunlight or humidity and store the pen in a dark place. Occasional cleaning with a soft cloth is sufficient to maintain its beauty.
Photos are for reference and may differ slightly from the final product.
Brand history & philosophy
Eboya is the flagship brand of Nikko Ebonite Manufacturing, founded in 1952 and recognized as Japan’s last specialist ebonite manufacturer. 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 a deeply Japanese design sensibility. 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, and finely finished writing instruments.
"A jewel that unites Japan’s spiritual tradition with writing excellence."
