Last month I had my first encounter with KWZ Ink. My impressions of the iron gall inks was mixed: the iron gall green #3 I really liked, the iron gall red #3 a lot less. The IG turquoise is the third iron gall KWZ Ink I tried. Fresh on the paper and in the bottle it might look like a turquoise, within seconds it's far more dark and in my opinion this is more a teal than a turquoise. A modest, nice color for both professional or personal purposes.
The ink is well behaved, a bit more prone to feathering than other KWZ inks than expected. Shading is low to moderate, show-through minimal. The ink is not too wet, writes smoothly and drying times only a bit above average. Water resistance is OK, be quick and there won't be too much damage.
The color is not unlike Iroshizuku's Tsuki-yo. Both are more blue than Emeraude de Chivor (Herbin) and Syo-ro (Iroshizuku).
All is all this is a decent ink in a nice modest color, for a good price. There is only one problem, the ink lacks excitement. Decent marks all over, but nowhere excellent. That makes the ink a bit too much a dime a dozen.