Question: how good is zdp 189?
Answer: Thanks to its very high hardness (64-66 HRc compared to the average of 58-62 HRc), ZDP-189 can be ground thinner and sharpened less often. This makes for a great slicing knife and a perfect steel, in my opinion, for a regular-use, everyday-carry folder. ZDP-189 can tarnish, though not as easily as 3V.