This is one of several 1000 grit stones available among the Nubatama Synthetic Japanese Waterstones. This particular one is part of the Ume or plum series. Most notable for it's georgeous speckled pattern, it is a particularly beautiful stone that sharpens as well as it looks. A popular synthetic stone used by sword polishers, it also works superbly with knives. In this video I use it to help refine the geometry of a carbon steel kurouchi nakiri with a zero grind edge - the edge is continuous with the side of the knife. More porous than a Shapton stone, it is comparable in porosity to Choceras and after a brief run under the tap of a couple minutes stays saturated fairly quickly. Rapidly abrades, producing a fine dark mud loaded with swarf. Doesn't load up, keeps cutting . Maintains a noise level comparable to other 1k stones, although a bit higher in pitch. Leaves an excellent hazy edge and appears to give a differential finish between the soft cladding and hard core steel on this carbon steel knife. I conclude by demonstrating the knife easily both slice and push cutting standard copy paper.
This is a pleasurable stone to work. It is fairly hard. There is no danger in cutting into the stone, so edge leading and trailing strokes are not a problem at all. Highly recommended for amateur and pro alike, whether this is your first stone or your thousandth.