Platinum Chou Kuro Black Ink 60ml

The Platinum Chou Kuro Black Ink 60ml is the darkest ink Platinum has made in its 104 year history. The name translates as "ultra black", and the claim holds up: measured, this ink is 46.8% darker than the already deep Platinum Carbon Black. No blue or grey undertone, just a solid matte black line. If you are after the blackest fountain pen ink available, the search ends here.

The colour forms in an unusual way: the pigment particles react with the minerals in the paper as you write. The result is an opaque, intensely black line that barely shows through. Once dry the ink is waterproof and fade resistant, which makes it ideal for letters, journals and documents you want to keep for years. On fountain pen friendly papers such as Tomoe River or Rhodia the depth of black really comes through.

Like every pigment ink, Chou Kuro asks for a little care. Do not let it dry inside the pen, and flush it regularly if the pen sits unused for several days. One point specific to this ink: clean the pen with distilled water rather than tap water. Tap water carries minerals that react with the ink and leave stains that are hard to remove. With that small bit of care you keep the deepest black ink on the market performing at its best.

• Platinum's blackest fountain pen ink, 46.8% darker than Carbon Black.
• Pigment ink, waterproof and fade resistant once dry.
• Matte black line with no blue or grey undertone.
• 60 ml glass bottle. Clean the pen with distilled water.