This is the Sailor Kiwa-Guro Nano Black Ink made by the same company that produces those wonderful fountain pens. The ink's made in Japan. Actually, I though it should be read as Kiwa-Kuro instead because the Japanese Hiragana characters seems to read that way.
The packaging is nice. I love the shape of the bottle. It has a wide base.
The opening is large so it's comfortable to fit your pens inside. Inside the bottle there's an inverted plastic cone.
The cone's a very smart idea to help you fill your pen. According to the instructions, before filling, you should invert the bottle before turning it upright. As you turn the bottle back upright, the ink will flow into the plastic cone. And you fill your pen with ink from that plastic cone instead of dipping the whole pen into the ink bottle like with other brands. This way, you don't have to clean your pen that much after filling. Nice.
This is a fountain pen ink with nano pigments. It's still a pigmented ink so be careful not to let it dry out in your fountain pen.
I've tested it on my fountain pen and the ink writes smoothly and dries fast to an intensely dark matte surface.
Just for some kicks, I tested it as usual with a dip brush. Below are the close ups.
It's a bit patchy when used this way as compared to other black inks I've reviewed.
You can't see in this scan but areas where the ink is concentrated will dry to a slight sheen. It's not an issue to those write with the ink.
When dry, the ink's smudge proof, permanent and resistant to erasing.
The Sailor Kiwa-Guro is an expensive ink just like the Platinum Carbon Ink reviewed recently. It's too expensive to be used for filling black areas if that's only purpose is bought for. There are more economical choices.
Another small note is the ink smells funny.
It's a fantastic fountain pen ink that's intensely dark and dries fast. Nano pigment or what, the usual care should still be taken when using pigmented ink in fountain pens.
When I bought the ink and used it for the first time, it was waterproof. After a few months, it seems to have lost its waterproof characteristic. That's really strange because I've not known of other inks that do the same. So if you use the ink months later, note that it's not going to be totally waterproof and hence not suitable for use with watercolour. It will smear slightly with water.
This is a pricy ink, even more expensive than the Platinum Carbon Ink. It's a good performing ink though so it's still worth the money.