I had the chance to try the 3k stone before it was available to the public to give Yasuko my opinion about it. It's been a while but here's basically my assessment. The majority of my tests were done with polishing in mind but I did some tests for the the cutting edge too.
(Video below on a cheap western knife for the cutting edge and core polishing)
Firstly, it is a soft stone. I would say that it is halfway between a Naniwa pro and imanishi arashiyama on the felt side. For a polishing point of view I like my stone softer but I really prefer a hard one for sharpening. My favourite for sharpening is Naniwa pro 3k.
I'm always a little skeptical when people talk to me about a mix of natural and synthetic stone. In my opinion, it plays more on the marketing side than the real performance gain. But by removing this variable, I found the stone pleasant to use. Natural stone used in this one is mikawa nagura.
The hagane was very shiny and mirror-like with a uniform scratch pattern. The grain size is, in my opinion, a little finer than indicated. This stone can burnish really fast, It's an advantage or a disadvantage, it all depends on what the person is looking for. Mud production is generous, easy to flatten, cutting is fast and lots of material (it's really thick).
But even though I liked this stone in general, it goes to sleep and I never use it. I always come back to Naniwa when polishing or Shapton when sharpening. I must admit that I am now more curious to try the 1k. But I've tried so many stones that now I stick with my favorites and I no longer want to waste money trying a new stone, especially when I always use the same ones!
I am actually curious to see the opinions of other members about these stones.
I found the video that I had sent to Yasuko.
