Ishimaru’s Color Bar - Rainbow

Color Bar Rainbow (No. 92) Ink drop

Color Bar, the in-house brand of the Nagasaki-based Ishimaru Bunkoudou chain of stationery stores, releases several additions to the extensive collection each year. Rainbow (number 92 in the series) was launched at the Tokyo International Pen Show on November 1, 2025. I picked up a bottle two weeks later, at the Autumn 2025 Seoul Pen Show.

Ink Swatches on Cosmo Air Light and Tomoe River

Almost all of the collection’s inks are named for cocktails, but I have to admit that I don’t know the drink that possibly inspires this ink. The color of the ink is accurate and clear on the bottle and packaging image, but I still wasn’t sure what to expect given the name. What I did find is a caramel brown (on most papers) that barely contains its colorful components. In swatches and writing on many papers, there is a powdery visual quality that reveals traces of greys, pinks, violets, and blues, and on Takasago Bank paper it jumps directly into a pinkish and reddish, amber orange-brown. You get hints of this complexity in the nice shading, but when used with a water wash or water brush, the rainbow inspiration becomes much more apparent.

Ink Swatches on Iroful and Takasago Bank papers

Color Bar inks are always good writing inks in my experience. Rainbow, like the others I have reviewed, has a nice neutral to wet flow and consistency. It has a very pleasant feeling as strokes fill the page. In performance, it is consistently clean and crisp with a dark stroke profile. You’ll see the tiniest examples of micro-feathering in my close-up writing sample image, but they are not something that comes to mind as you write, and they aren’t noticeable at all unless you zoom in with a lens. This is a nice writing ink.

Color Bar Rainbow Writing sample on Cosmo Air Snow paper

You can find Rainbow (and the 91+ other Color Bar inks) at Ishimaru stores in Japan, or through select retailers. You can also order them directly online at www.ishimaru-bun.co.jp. Along with Color Bar, Ishimaru has several other collaboration series available, and much, much more.

Color Bar Rainbow ink swatch card

Color Bar Rainbow ink swatch card comparisons

Color Bar Rainbow 23 ml ink bottle and box