Eboya Hakobune Shinkai Deep Sea Medium Fountain Pen
The Eboya Hakobune Shinkai Deep Sea Medium Fountain Pen is handmade in Tokyo from blue-and-black marbled ebonite. Its clipless profile, warm surface and 14K gold nib create a writing instrument with a calm but distinctive presence. The medium-sized body is suited to regular writing, while the non-repeating Shinkai pattern makes every finished pen visually unique.
The meaning behind Hakobune and Shinkai
Hakobune (方舟) means “ark” or “large vessel”. The name reflects the stable cylindrical shape of the pen and the quiet sense of movement suggested by its uninterrupted, clipless silhouette. Medium refers to the size of the body rather than the nib grade, which is selected separately.
Shinkai (深海), meaning “deep sea”, is one of Nikko Ebonite Manufacturing’s original colour mixtures. Rich blue areas flow through a black ebonite base, producing irregular veins that recall ocean currents and changing depths. Because the material is mixed and turned individually, the position and intensity of the blue pattern will vary naturally from one pen to another.
Designed for everyday writing
The Hakobune Medium is fitted with a narrow Bock number 6 nib made from 14K gold. Each nib is adjusted by the craftspeople at Nikko Ebonite Manufacturing to provide controlled and consistent ink flow. Available grades include Fine, Medium Fine, Medium and Broad, subject to stock. The ebonite body feels warmer than metal or conventional acrylic and remains comfortable during longer writing sessions.
An international cartridge and converter filling system provides useful flexibility. A standard European-type cartridge is convenient when travelling, while the included converter allows the pen to be filled from an ink bottle. The body unscrews from the section so that either filling component can be installed securely.
Package contents
- Eboya Hakobune Shinkai Deep Sea Medium Fountain Pen
- Standard international converter
- One ink cartridge
- Premium paulownia wood box supplied to Inktraveler instead of the standard cardboard packaging
- Warranty
(Product photographs are for reference. The marbled pattern will vary because every ebonite body is individually made).
Technical specifications
- Brand: Eboya
- Model: Hakobune
- Body size: Medium
- Material: original marbled ebonite by Nikko Ebonite Manufacturing
- Colour: Shinkai, deep blue with black veining
- Closed length: 142 mm
- Barrel diameter: 15 mm
- Cap diameter: 15 mm
- Approximate weight: 24 g
- Nib: Bock nib in 14K gold
- Available nib grades: F, MF, M and B, subject to availability
- Filling system: international cartridge or converter
- Cap closure: screw-on
- Design: clipless
- Handmade in Tokyo, Japan
Other Hakobune colours
Hakobune fountain pens are produced in several marbled ebonite colours developed over a black base. Browse other Eboya ebonite fountain pens or ask about the availability of these finishes:
- Tanshin – Red
- Nichibo – Orange
- Kogetsu – Yellow
- Wakaba – Yellow green
- Kunpuu – Green
- Shinkai – Blue
- Shinryu – Beige
- Black Ebonite – Solid black
Frequently asked questions
Does Medium describe the nib?
No. It identifies the body size. The nib grade is chosen independently from the available options.
Will every Shinkai pen look identical?
No. The blue and black areas form differently in every ebonite blank, so variations in veining and colour balance are expected.
Can this pen use cartridges?
Yes. It accepts standard international cartridges and can also be filled from an ink bottle with the included converter.
Can another size or colour be ordered?
A special order may be possible while Eboya continues to manufacture the requested combination. Because production is carried out by hand, lead times can extend to several months.
Care and storage
Protect the ebonite from prolonged sunlight, excessive heat and humidity. Store the pen in a dark place when it is not being used and remove dust occasionally with a soft, dry cloth to help preserve its natural finish.
From ebonite manufacturer to fountain pen maker
Eboya is the fountain pen brand of Nikko Ebonite Manufacturing, founded in 1952 and recognised as Japan’s last specialist ebonite manufacturer. After supplying the material to established Japanese writing brands for decades, the company introduced its own fountain pen collection in 2009. The pens are turned, polished and adjusted by hand in its Tokyo workshop.
Ebonite is produced by vulcanising natural rubber with sulphur. Its warm feel, durability and understated sheen made it an important material in early fountain pen production. The Hakobune Shinkai brings those qualities into a modern writing instrument whose deep-sea colour, comfortable proportions and visible craftsmanship are intended to be appreciated through regular use.
“Like a vessel crossing deep water, every line moves forward with its own quiet rhythm.”
