This video is about the 3000 Nubatama Bamboo, which is similar in composition to the 2000 grit Bamboo stone. I would strongly recommend reviewing the video of the 2k Bamboo stone to see how well that stone works on Carbon steel knives to produce a Kasumi finish with excellent contrast between the hagane or core steel and the cladding or jigane. This 2k Bamboo is one of the more exceptional stones I've ever used.
I will be using a wide range of knives for this initial impression. First a Moritaka 'mini-nakiri' similar to a producer's knife - used to slice fruit and vegetable samples and chopping chilies and garlic. This is a blue steel #2 carbon steel clad knife, previously sharpened using the usual synthetic stones.
Next is a Hiromoto AS 300 mm sujihiki, with an Aogami Super core carbon steel with a nicely developed patina and stainless steel cladding.
Next is a single beveled knife of Blue #2 steel, an Aritsugu (from Tsukiji) 270 mm Kiritsuke. It combines the three traditional single beveled knives functions of a yanagi, usuba and deba. It is a very specialized knife with a thin tip and a stout heel.
Next is a Global knife, which uses a soft stainless steel knife - very different from the other knives selected just to demonstrate the versatility of this stone in addition to it's special properties.
Porosity testing of this off white pale green stone when dry follows. It is very smooth even dry. It absorbs water quickly initially, yet holds it's water well, not requiring frequent refreshing.
The Moritaka goes first. VERY silky smooth quiet stone quickly producing a fine metal swarf, considerably finer metal swarf than the 2k Bamboo. There is almost an immediate increase in contrast between the ha and ji (gane). Edge trailing and leading strokes are not a problem. It is immediately apparent that this stone will be a superb precursor or lead in to using natural stones with a bright finish on the hard core steel and a very uniform scratch pattern on the soft steel. As the mud thickens, it can be used to advantage. I 'play' with the mud, demonstrating a staircase pattern in the mud (for the hell of it ) to show off the mud.
Consider using awasedo or natural polishing stones such as the Yaginoshima Asagi or Hakka Tomae following this stone
Next the Kiritsuke. Continuing with the same mud, I notice that the mud acts as a cushion, further improving the refinement of the stone's scratch pattern and further reducing the sound level.. The stone doesn't require adding much water during use. The resultant finish is both high contrast but not garrish with the single bevel showing smooth scratch pattern on the jigane and a clear clean finish on the hagane.
Next the Hiromoto AS. After finding the angle previously used with an edge leading stroke, I continue using the previous mud from the Aritsugu knife. Little additional water is required. The edge produced is a clean mirrorlike finish. Cutting performance is excellent for slice cutting and good push cutting.
Next the Global. It immediately begins cutting steel. NO loading occurs, even at low water levels where you have higher grit density. I inadvertently demonstrate how a wet piece of paper ruins a cutting test. A dry piece piece of paper easily slice cuts and push cuts.
I also discuss when one might prefer a 3k Bamboo vs a 2k Bamboo. Although these stones are somewhat more expensive than other stones, if you are able to splurge on a stone to experience how this stone works, I would highly recommend purchasing one of these. A true pleasure. The edge can easily work as a final finish for multiple applications from carbons to everyday easy to care for knives like the Globals.