Kakimori x TSUKI no IRO: Pigment Ink

A collaboration between Hobonichi and Kakimori: this pigment ink was developed exclusively for the TSUKI no IRO series and features the characteristic blue-grey tone of the Hobonichi Techo Standard's millimetre-ruled paper. The deep, slightly cool colour integrates seamlessly with the pages of the Techo – when you write on it, the ink feels like an integral part of the notebook, not an afterthought. The foundation is Kakimori's water-based pigment formulation, developed in collaboration with Japanese colour specialist Turner Colour Works.

Features

• Pigment-based, not dye-based: Water and light-fast after drying. Your writing and notes remain permanently legible – even if a page gets damp or the Techo sits on your shelf for years.
• Exclusive collaboration colour: The blue-grey is not a standard Kakimori shade, but an original colour developed specifically for TSUKI no IRO, matched to the colour of the millimetre-ruled paper in the Hobonichi Techo Standard.
• Optimised to prevent clogging: Kakimori's pigment formula is specifically designed to minimise ink drying in the nib – a typical problem with pigment inks. With regular use, the ink flows reliably.
• Glass bottle with plastic cap: The glass body feels solid and stable in your hand. The cap, made from AS resin (acrylonitrile-styrene), seals tightly and protects the ink from evaporation and light exposure.
• Made in Japan: Both ink and bottle are produced in Japan, where Kakimori has been manufacturing since its founding as a stationery shop in Tokyo.

Use & Tips

• Fountain pen: The ink is suitable for fountain pens. For pigment inks, a fountain pen that is used regularly – ideally daily – is recommended, so the ink doesn't dry in the nib. Should it happen anyway: simply rinse the nib with clear water.
• Dip pen and glass pen: Thanks to its pigment-based formulation – thicker than pure dye inks – this ink is also excellent for dip pens and glass pens.
• In the Hobonichi Techo Standard: The colour tone is matched directly to the printed grid of the Techo. Entries look calm and cohesive – perfect for anyone who wants their planner to feel visually unified.
• Shake before use: Pigment inks settle when standing still. Gently shake the bottle before each use, so the pigments and carrier liquid mix evenly.
• Storage: Keep in a cool, dry place, away from light. Direct sunlight accelerates the ageing of the pigments and the rubber seal.
• Mixing: Kakimori pigment inks can be mixed with each other – only with other inks from the same range, not with dye-based inks from other manufacturers.

For Ink Enthusiasts

Kakimori's pigment formulation arose from a desire to overcome the classic drawbacks of pigment inks – dull colours, tendency to clog, poor mixability. In cooperation with Turner Colour Works, a formula was developed that keeps pigment particles small enough not to block fountain pen mechanisms, but large enough for genuine light-fastness. The result: an ink that is permanent (water and light-resistant after drying) but handles as conveniently in everyday use as a good dye-based ink. The TSUKI no IRO shade is not simply a recoloured existing shade – it was developed as an independent original colour specifically for this collaboration and is visually inspired by the cool blue-grey of the printed grid lines in the Hobonichi Techo Standard.

Technical Specifications