Pilot iroshizuku Fountain Pen Ink Cartridge - Ku-jaku

Pilot Iroshizuku Fountain Pen Ink Cartridges — Ku-jaku (Peacock)

Ku-jaku means peacock in Japanese, and the name earns its keep. This is a deep, saturated teal that reads as something between a rich blue and a forest green depending on the light, the paper, and the nib you're writing through. It is one of those colours that rewards attention - complex enough to feel considered, wearable enough for everyday use.

The Iroshizuku line has been a touchstone of serious fountain pen culture since its launch in 2007. Developed by Pilot in Japan, it was conceived as a tribute to the natural landscapes of the country: its skies, blossoms, rivers, and fauna. Ku-jakudraws from the iridescent plumage of the peacock, and the colour achieves exactly that quality - vivid, layered, and never flat.

The Ink
Ku-jaku performs well across the range of papers you're likely to use it on. Flow is smooth and consistent, it dries quickly, and it cleans out of a pen without fuss - though the deeper blue and green pigments may ask for an extra rinse or two. Shading is present but restrained: the ink shows variation between thick and thin strokes without becoming theatrical about it. The result is writing that looks deliberate and alive.

What's in the Box
Each box contains six proprietary Pilot ink cartridges, each holding approximately 0.9 ml of ink. The packaging is designed to reflect the aesthetic of Iroshizuku's celebrated glass bottle line: the inner tray slides out cleanly and is fitted with a latch to keep it from separating from the outer sleeve entirely. Each cartridge is printed with the name of the colour.

Compatibility
These cartridges are proprietary to Pilot and Namiki fountain pens. They are compatible with a wide range of Pilot models including the Custom 74, the Vanishing Point, the Cavalier, and the Décimo, among others. They are not compatible with standard international cartridge systems, so please confirm your pen accepts Pilot proprietary cartridges before ordering.