This is a review of the Organics Studio Carbon ink. The line is discontinued but there are one or two stores with some stock left. This is a nice dark grey ink. Not very waterfast though. Somewhat similar to Iroshizuku take-sumi, but a little lighter than that ink.
The ink is a bit of a slow drier.
The ink droplet shows a hint of purple that isn't really noticeable in the ink.
Not very waterfast. Much of the ink lifts when blotted, and when washed it leaves a faint line.