Kiwa-Guro Black is one of Sailor’s “luxury” inks, more costly than their standard Jentle line. This is one of Sailor’s two pigmented inks, made with ‘nanoparticles’ – they also make a blue-black called Sei-Boku.
Pigmented inks are different from dye-based inks (most other fountain pen inks) in that they are made with micro-fine pigments suspended in the liquid to give the ink its colour. In order to make these safe for fountain pens – to prevent persistent clogging or flow issues – these particles are really micro-fine, and the inks are designed for fountain pen use.
Be careful not to mix these up with the inks that are not okay for fountain pens – India ink, calligraphy ink (thicker, to hold a little better to dip pens) or inks that have shellac in them. These inks will definitely clog up your fountain pen’s feed, and may even cause more permanent damage.
The writing sample was done with Noodler’s Nib Creaper Flex fountain pen.
This ink, because it’s a pigment ink, offers a really rich, deep black colour. It’s not the blackest black you will get (I think some consider Noodler’s Black the blackest you can get), but it is one of the deepest blacks you can get. It’s a dense black, with no shading at all, even with a flex pen. On the Rhodia, there’s no feathering or bleeding, but it’s generally a pretty good ink. This is definitely a crisp, dark, clean line.
This ink is definitely smooth. Sailor’s inks are generally very smooth, and this ink is no exception – it glides across the page.
This ink behaves very well, and while I have read reviews that found it long to dry, I found it to be not bad at all in dry time. It’s a sophisticated black ink for the office, but it’s fairly waterproof as well. However, one of the things I love most about this ink is that it’s kind of got this balance between being super matte when you look at it head on and having just a hint of sheen when you look from an angle.
You shouldn’t have any clogging issues if you have generally good pen habits. This is not an ink you want to leave to dry out in your pen – not that you’d want to leave any ink to dry out in your pen.
I would suggest that you at least scribble a bit with your pen to get things flowing every other day or so to be on the safe side. Even when using this ink again on a refill, you may want to clean out your pen between each filling (rather than just refilling directly) just to get any particles moving out.
It is more expensive than the inks in the Jentle line, but in my opinion (as a retailer!) it’s worth it – it’s a rich, smooth, dark black. You can find it here.