# Soft and muddy synthetic stones



## dafox (Jul 24, 2020)

I'm wanting to get more of these to sharpen wide and single bevel knives, what's out there?


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## MrHiggins (Jul 24, 2020)

I'm no expert on stones, but my Gesshin 1000 (XL) is soft and muddy as hell. I love that stone, but it does require a lot of flattening. I'd probably also call my Gesshin 6000 soft and muddy if you're looking for something higher grit.


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## Carl Kotte (Jul 24, 2020)

King Deluxe and King hyper. Muddy muddy muddy.


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## Knife2meatu (Jul 24, 2020)

Carl Kotte said:


> King Deluxe and King hyper. Muddy muddy muddy.


Do you have the Soft Hyper?

[if so, there's a pill for that -- sorry, couldn't resist]


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## Barclid (Jul 24, 2020)

The entire Cerax series/"Professional" series from Suehiro
King Deluxe
King Hyper 1k standard/soft
King Hyper 2k
King Neo 800 (middling soft)
Jon's super secret resin 1k which is amazing but not on his website
Arashiyama (resin - middling hardness)
Kitayama (resin - middling hardness)
Gesshin 400
Gesshin 2k
Naniwa Chosera/Pro 1k, 800, 600, 400 (Easily soft enough for wide bevels, unlike most of the rest of the series. Higher grits are too hard)
JNS 400, 800
Sigma Power Select II 400, 1k and 13k (rest of the series not so much - 3k and 6k both leave harsher scratch patterns)
Naniwa Super Stones
Shapton 220, 320 and 2k Kuromaku (2k only if you work up a mud - useful as a pre-JNat as it's fast and easy to see residual scratches but it's not going to look nice as a solo finisher. 320 and 220 are pretty muddy)
Shapton Glass 500 (Not really soft, but when hitting soft cladding it can mud up and works pretty well for wide bevels)

This is not really exhaustive. There are tons of stones out there. The entire Cerax series is the most consistently muddy in my experience.


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## Carl Kotte (Jul 24, 2020)

Knife2meatu said:


> Do you have the Soft Hyper?
> 
> [if so, there's a pill for that -- sorry, couldn't resist]


Sorry I didn’t get that. There was a joke there, right? 
King hyper 2k was the one I was thinking of.


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## kayman67 (Jul 24, 2020)

Sigma Power Select 2 3000 has a finer finish than 1000. Just needs some soaking. With all stainless the finish was finer, haze like.


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## Carl Kotte (Jul 24, 2020)

@Barclid That was one comprehensive list! Great!


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## Barclid (Jul 24, 2020)

kayman67 said:


> Sigma Power Select 2 3000 has a finer finish than 1000. Just needs some soaking. With all stainless the finish was finer, haze like.


Well yeah... It's a 3k. My point was that for a 3k, it leaves a relatively undesirable finish. The Cerax 3k finish is far more desirable on pretty much any steel in my opinion. The Sigma 1k is for sure muddier though.


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## Barclid (Jul 24, 2020)

Carl Kotte said:


> @Barclid That was one comprehensive list! Great!


See? I AM capable of expressing more than just angry thoughts.


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## Carl Kotte (Jul 24, 2020)

Barclid said:


> See? I AM capable of expressing more than just angry thoughts.


You seem angry again (slowly backing away - moonwalking).


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## ian (Jul 24, 2020)

Why do people like coarse grit soft/muddy stones? Just because they often cut fast? I feel like if you're looking to polish a wide bevel then a soft/muddy coarse stone is counterproductive unless you're actually going to finish on that grit.


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## Barclid (Jul 24, 2020)

Carl Kotte said:


> You seem angry again (slowly backing away - moonwalking).


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## Barclid (Jul 24, 2020)

ian said:


> Why do people like coarse grit soft/muddy stones? Just because they often cut fast? I feel like if you're looking to polish a wide bevel then a soft/muddy coarse stone is counterproductive unless you're actually going to finish on that grit.


Cutting speed is more important sometimes.


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## Carl Kotte (Jul 24, 2020)

Barclid said:


> View attachment 88225


That’s what sea said!


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## Barclid (Jul 24, 2020)

There's also the matter of layering scratch patterns, which others who have polished wide bevels can probably attest to. You often see darker contrast on later stones when starting with muddier, deeper contrast base stones. If the stone is too hard you might remove any contrast and then struggle to add it back with a muddier finer grit stone.


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## ian (Jul 24, 2020)

Barclid said:


> There's also the matter of layering scratch patterns, which others who have polished wide bevels can probably attest to. You often see darker contrast on later stones when starting with muddier, deeper contrast base stones. If the stone is too hard you might remove any contrast and then struggle to add it back with a muddier finer grit stone.



Won’t you ideally just remove the previous scratch pattern, though? Or are you describing a time saving measure that many people use in practice, where you get reasonable contrast on a coarse stone and then even it out a bit on a higher grit stone?

I’m playing devil’s advocate here a bit, since I have a Gessh 400 and really like the speed. But it does hide uneven geometry.


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## Barclid (Jul 24, 2020)

ian said:


> Won’t you ideally just remove the previous scratch pattern, though? Or are you describing a time saving measure that many people use in practice, where you get reasonable contrast on a coarse stone and then even it out a bit on a higher grit stone?
> 
> I’m playing devil’s advocate here a bit, since I have a Gessh 400 and really like the speed. But it does hide uneven geometry.


In a perfect world you'll remove the effect of the previous stone entirely, I suppose. In reality, you don't usually. You can get a finish that visibly has none of the previous grits' scratches while maintaining some of the contrast from that previous stone into the next stone. So you achieve a finer finish but the layering effect of the stones has netted you deeper contrast. Does that make sense? If you try to take a Cerax 8k, which leaves remarkably deep contrast for an 8k, to a mirror-polished ni-mai wide bevel, you would not get nearly the same contrast by the time you established an even finish versus a progression from say, 1k Cerax to 3k Cerax to 8k Cerax. You would have a nice 8k looking finish in the second progression and deeper contrast unless you really took so long that you perfectly removed the effect of each preceding stone.


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## ian (Jul 24, 2020)

Barclid said:


> Does that make sense?



Not completely. If you remove all the previous grit’s scratches, how does contrast remain? What physically _is_ contrast? (I know what it looks like, but what’s going on...) Naively, it seems like contrast would be more surface level than the deeper scratches, so if you remove the scratches you remove the contrast. Or is contrast something about the quality or bottoms of the scratches?


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## kayman67 (Jul 24, 2020)

Barclid said:


> Well yeah... It's a 3k. My point was that for a 3k, it leaves a relatively undesirable finish. The Cerax 3k finish is far more desirable on pretty much any steel in my opinion. The Sigma 1k is for sure muddier though.


Sigma 1000 can take good care of 220 scratches with little effort. 3000 seemed fine to me, but I imagine expecting something else makes it undesirable.


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## kayman67 (Jul 24, 2020)

ian said:


> Not completely. If you remove all the previous grit’s scratches, how does contrast remain? What physically _is_ contrast? (I know what it looks like, but what’s going on...) Naively, it seems like contrast would be more surface level than the deeper scratches, so if you remove the scratches you remove the contrast. Or is contrast something about the quality or bottoms of the scratches?


Contrast is more about layer chemical reaction than pure scratched surface. Might go a bit deeper. Not sure if this applies to every type of alloy in the same way.


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## Barclid (Jul 24, 2020)

ian said:


> Not completely. If you remove all the previous grit’s scratches, how does contrast remain? What physically _is_ contrast? (I know what it looks like, but what’s going on...) Naively, it seems like contrast would be more surface level than the deeper scratches, so if you remove the scratches you remove the contrast. Or is contrast something about the quality or bottoms of the scratches?


I don't pretend to have perfect understanding of the science behind it, it's just what I observed from sharpening many different wide bevel knives. Chemical reaction almost certainly has something to do with it, and variance of particle size is very likely another contributing factor. If you've ever hand sanded a stone finished knife and you've seen the deeper scratches that take longer to take out from just, say, a 1k stone then you've already observed how a single stone can leave scratches of differing depth. Add that, but on a smaller scale, and you could ostensibly introduce greater occlusion within the cladding with the myriad scratches from particles found in the slurry.

Again, this is just an educated guess based on experience. I haven't done any scientific testing or found any literature which explores it in depth on a purely scientific basis.

We know that etching knives with acid creates darker finishes and we can observe that certain stones, mostly JNats, will discolor the steel above the Shinogi line while polishing which points to stones with a different pH level or other chemicals like sulfur present in the stone which can have a discoloring effect. In the case of synthetic stones I think it's more likely due to scratch-based occlusion but I also haven't tested slurry of those stones so who knows?


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## Barclid (Jul 24, 2020)

kayman67 said:


> Sigma 1000 can take good care of 220 scratches with little effort. 3000 seemed fine to me, but I imagine expecting something else makes it undesirable.


I agree that the 3k is fine in a progression, but it's not really appealing to me as a final finish.


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## ian (Jul 24, 2020)

Barclid said:


> In the case of synthetic stones I think it's more likely due to scratch-based occlusion but I also haven't tested slurry of those stones so who knows?



That’s what I was assuming. I was just confused because if that’s the case, presumably those scratches are less deep than the ones you’re trying to remove with the higher grit stone, so they should disappear first, right?

But maybe this is all happening at the bottom of the deeper scratches.


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## ian (Jul 24, 2020)

kayman67 said:


> Contrast is more about layer chemical reaction than pure scratched surface. Might go a bit deeper. Not sure if this applies to every type of alloy in the same way.



Weird. It would seem strange to me if a chemical reaction coming from a few minutes on a stone took longer to get rid of than the scratches. Or maybe the bottom of the scratches are the part that’s most colored by the reaction, since that’s the exposed metal? Interesting.


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## kayman67 (Jul 24, 2020)

I can tell you this. Me doing a pure chemical finish on a blade and trying to remove that with sandpaper is much harder work than I would have imagined. Seems like it goes a lot deeper than I initially considered it would. Also, the longer I let it interact, the harder it gets to remove. This seems pretty obvious, but again, goes deeper than I expected. 
Some synthetic stones have at least some chemical reaction with the alloys. They aren't all inert. These seem to work better. Thus some layering must be going on to some degree.


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## ian (Jul 24, 2020)

kayman67 said:


> layering



What’s layering mean here, specifically? I get that you’re referring to a chemical reaction.


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## kayman67 (Jul 24, 2020)

For a better word, I consider this just how deep the effect would be. Removing a "layer" from that alloy might not change much there, but would polish another part that's affected in a different way by earlier interactions.


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## Barclid (Jul 24, 2020)

Yeah, I can definitely echo some synthetics reacting with various steels. Notably and probably most commonly the Kitayama and Arashiyama have that effect on carbon.


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## M1k3 (Jul 24, 2020)

My uneducated guess what's going on, is the scratches are random enough to not reflect light directly at the eye.


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## ojisan (Jul 24, 2020)

Suehiro 1000/3000 (SKG series) is really soft and muddy.


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## Knife2meatu (Jul 25, 2020)

Naniwa 2k Aotoishi green brick is muddy on my iron-clad carbon. It's resin, so it's kinda soft, but it's also relatively hard for resin. If that makes sense.

I've found it quite underwhelming for cheap soft mono-stainless, however; despite what's often said. It mostly loads and doesn't slurry with those. Decent enough for finishing, I guess; but stone is dummy thicc for that application alone.

I don't know how it works with soft stainless clad knives. If it behaves with stainless cladding as it does with iron, it'd be nice in my book.


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## zizirex (Jul 25, 2020)

Barclid said:


> Well yeah... It's a 3k. My point was that for a 3k, it leaves a relatively undesirable finish. The Cerax 3k finish is far more desirable on pretty much any steel in my opinion. The Sigma 1k is for sure muddier though.


How do you compare Cerax 3K to other Suehiro stones? I am considering Cerax 3k, Ouka 3K and Rika 5K. it's just for polishing purposes since Naniwa Pro 3K is not the easiest stone to do the polishing job. I'm also looking at Hayabusa 4K since I am looking mid-fine grit stone that is less than $100.


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## Knife2meatu (Jul 25, 2020)

Seeing as how there's no Cerax 3k, it's likely only the Ouka.

Forgot about New Cerax, nvm.


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## kayman67 (Jul 25, 2020)

M1k3 said:


> My uneducated guess what's going on, is the scratches are random enough to not reflect light directly at the eye.


Could be. Could be both.


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## M1k3 (Jul 25, 2020)

@nutmeg would probably know.


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## Barclid (Jul 25, 2020)

zizirex said:


> How do you compare Cerax 3K to other Suehiro stones? I am considering Cerax 3k, Ouka 3K and Rika 5K. it's just for polishing purposes since Naniwa Pro 3K is not the easiest stone to do the polishing job. I'm also looking at Hayabusa 4K since I am looking mid-fine grit stone that is less than $100.



Cerax 3k and Ouka 3k are the same. Rika 5k and Cerax 5k are the same. Get whichever is cheaper or you like the packaging/mounting of I guess. Haven't used Hayabusa but the Cerax fine grits are all muddy soakers.


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## Ruso (Jul 25, 2020)

Barclid said:


> Cerax 3k and Ouka 3k are the same. Rika 5k and Cerax 5k are the same. Get whichever is cheaper or you like the packaging/mounting of I guess. Haven't used Hayabusa but the Cerax fine grits are all muddy soakers.


You are not the first person from whom I hear that Rika 5K and Cerax 5K is the same stone, however I do not think this is true.
On Suehiro official web page Rika 5K and Cerax 5k (5050) are listed as 2 different stones.


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## Goorackerelite (Jul 25, 2020)

What’s the advantage of using a soft muddy stone vs using a harder stone?


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## Cliff (Jul 25, 2020)

I like soft and muddy to polish the blade face and hard stones to work on edges


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## Ruso (Jul 25, 2020)

Goorackerelite said:


> What’s the advantage of using a soft muddy stone vs using a harder stone?


Muddy stones are better in hiding low/high spots on a wide bevels.
Soft stones is probably the preference of the OP, but one could say that there are limited selection, if any, of hard muddy synth. Hence, soft and muddy goes hand in hand.


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## dafox (Jul 25, 2020)

Barclid said:


> The entire Cerax series/"Professional" series from Suehiro
> King Deluxe
> King Hyper 1k standard/soft
> King Hyper 2k
> ...


Thank you for that!!!


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## zizirex (Jul 25, 2020)

Barclid said:


> Cerax 3k and Ouka 3k are the same. Rika 5k and Cerax 5k are the same. Get whichever is cheaper or you like the packaging/mounting of I guess. Haven't used Hayabusa but the Cerax fine grits are all muddy soakers.


I think they are different in some way, but do you think overall is very similar that no one can really see the difference? same dish and muddy like crazy and polish beautifully? do they cut the same rate?

I know they are both have plastic stand/mount. Ouka has the baseless version though


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## Barclid (Jul 26, 2020)

Ruso said:


> You are not the first person from whom I hear that Rika 5K and Cerax 5K is the same stone, however I do not think this is true.
> On Suehiro official web page Rika 5K and Cerax 5k (5050) are listed as 2 different stones.





zizirex said:


> I think they are different in some way, but do you think overall is very similar that no one can really see the difference? same dish and muddy like crazy and polish beautifully? do they cut the same rate?
> 
> I know they are both have plastic stand/mount. Ouka has the baseless version though



I'm not "thinking" here. I'm telling you they're the same. It's direct from Okumura-san. There, I said it. Let the controversy end.

In fact, let me elaborate. The conversation went something like this:

Me: "Many people think your [Rika/Ouka/Shiramine/etc] are different from [Cerax 5000/Cerax 3000/Cerax 6000/New Cerax Line/etc]. Can you tell me the difference?"

Okumura-san: "They're the same."

Me: "Totally the same?"

Okumura-san: "The formula doesn't change. Possibly batch variation."


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## Ruso (Jul 26, 2020)

Barclid said:


> I'm not "thinking" here. I'm telling you they're the same. It's direct from Okumura-san. There, I said it. Let the controversy end.
> 
> In fact, let me elaborate. The conversation went something like this:
> 
> ...



Not that I do not trust you, but I find it hard to believe. What is the point of having multiple official lines that are the same stones.
Oh well, Japan I guess.


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## zizirex (Jul 26, 2020)

Barclid said:


> I'm not "thinking" here. I'm telling you they're the same. It's direct from Okumura-san. There, I said it. Let the controversy end.
> 
> In fact, let me elaborate. The conversation went something like this:
> 
> ...


okay, in terms of polish, which one gives better contrast? I will polish it out again with Uchi, so just a bridge between king hyper an uchi


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## Knife2meatu (Jul 26, 2020)

Whoa. This is really interesting re: Cerax 5050 Vs Rika.

Notably because Cerax 5050's description on the Suehiro site has it containing both WA & C, whereas Rika only ever lists WA.

I had an old thread wondering if Rika 5k, Cerax 5k, and 5000-AS are the same. (5000-AS gets sold on ebay was 'unlabeled Rika -- and apparently Stu from ToolsfromJapan may have sent those to Rika buyers)


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## Barclid (Jul 26, 2020)

And people still think all of the Sigma Power Select II are SiC or that they have no binder or both and that's not true either but they all say SiC on the website.

Anyway, believe it or not it doesn't matter to me.


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## Knife2meatu (Jul 26, 2020)

@Barclid Yeah... I've noticed that MTC's site sells Sigma select II 3k & 6k as alumina stones -- which isn't to impugn MTC's descriptions, which are broadly speaking the best around.

But that doesn't quite explain why both my 3k & 6k Select II have dark, greenish or blackish, flakes visible throughout both stones. Telltale sign of an abrasive mix, in all likelihood.


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## Barclid (Jul 26, 2020)

Knife2meatu said:


> @Barclid Yeah... I've noticed that MTC's site sells Sigma select II 3k & 6k as alumina stones -- which isn't to impugn MTC's descriptions, which are broadly speaking the best around.
> 
> But that doesn't quite explain why both my 3k & 6k Select II have dark, greenish or blackish, flakes visible throughout both stones. Telltale sign of an abrasive mix, in all likelihood.


They are alumina. Direct from Saicom. This has been covered before.


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## Ruso (Jul 28, 2020)

Barclid said:


> I'm not "thinking" here. I'm telling you they're the same. It's direct from Okumura-san. There, I said it. Let the controversy end.
> 
> In fact, let me elaborate. The conversation went something like this:
> 
> ...



I've send Suehiro an inquiry and they confirmed your facts. I still do not understand why, but perhaps they want to keep the Rika name as it pretty famous and well loved stone.


> Subject: RE: Mr.
> Date: Wed, 29 Jul 2020 09:52:33 +0900
> From: 株式会社 末広 <[email protected]>
> To: <blip>
> ...



I am not sure what do they mean by route, but perhaps different factories/contractors...


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## Barclid (Jul 28, 2020)

He means the market. He doesn't speak any English - he's using Google translate.


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## Ruso (Jul 28, 2020)

It is clear that their English is not the best. I actually was surprised to even get a response, and to be fair, a pretty quick one.
Thank you for clearing the lost in translation piece.


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## dafox (Jul 28, 2020)

I ordered a Suehiro Cerax 320, 1000, and Rika 5000 today. Thanks for your help all!


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## Ruso (Jul 28, 2020)

dafox said:


> I ordered a Suehiro Cerax 320, 1000, and Rika 5000 today. Thanks for your help all!


Post some impressions of the stones, especially Cerax 320


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## dafox (Jul 28, 2020)

Ruso said:


> Post some impressions of the stones, especially Cerax 320


Will do.


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## shinyunggyun (Jan 1, 2021)

Masahiro 1000. Super muddy and soft whetstone.


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## M1k3 (Jan 1, 2021)

If anyone is looking for a soft and muddy coarse stone that leaves a pretty even, not very scratchy finish (for it's grit), the 220 Naniwa Super/Sharpening Stone is it.


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