This is the second article in our series exploring the Wicked Edge Precision Sharpener (WEPS) stone progression under the microscope. In this installment, we’ll examine the complete Naniwa Chosera stone progression and see how each grit refines the edge. If you haven’t already, I recommend reading the article covering the stock Wicked Edge diamond and ceramic stones, as many of the concepts discussed there will help explain what you’ll see here.

For this demonstration, I used a Maestro Wu Bombshell Steel folding knife sharpened at 20 degrees per side. All microscope images were captured using a Veho 400x USB microscope, with each image covering an area approximately 1 mm wide by 0.75 mm high.

Transitioning from Diamond Plates to Chosera Stones

When sharpening a new knife or reprofiling an existing edge, I normally begin the Chosera progression after the 600-grit Wicked Edge diamond stone.

At first glance, this may seem like a step backward. The Wicked Edge 600 diamond plate has an abrasive size of approximately 16 microns, while the Chosera 400 measures around 30 microns. However, grit size alone doesn’t tell the whole story.

Diamond plates create deeper, more aggressive scratches because the diamonds protrude from a rigid metal surface. Chosera stones use a different abrasive and binder system, producing a shallower scratch pattern even at a coarser grit. As a result, the Chosera 400 begins removing the deep diamond scratches while replacing them with a more uniform finish.

The 400 and 600 Chosera stones are also excellent choices for maintenance sharpening and routine repairs without returning to diamond plates.

Although many sharpeners hesitate to move from a finer diamond grit to a coarser water stone, this transition actually improves the overall progression by creating a more consistent foundation for the finer Chosera stones that follow.

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Sharpening Technique

Throughout this progression, I use two primary sharpening strokes:

Scrubbing Strokes

Scrubbing strokes move straight up and down over a small section of the edge. Their purpose is to establish the new scratch pattern for each grit while compensating for slight variations caused by angle tolerances, stone wear, or minor inconsistencies in the bevel.

Sweeping Strokes

Sweeping strokes travel across the entire edge from heel to tip, alternating from one side to the other. These strokes refine the bevel, align the scratch pattern, and produce a cleaner apex.

Unlike my work with the coarse diamond plates, I generally reserve circle strokes for the 100-grit diamond stone and rarely use them with the Chosera stones.

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Using Slurry

Whenever I begin the Chosera progression after diamond stones, I like to raise a slurry on my coarsest Chosera stone. Depending on the knife, that may be the 400, 600, 800, or 1,000 grit.

A slurry is created by rubbing two stones of the same grit together after they have been soaked. This releases loose abrasive particles onto the stone surface, making the stone cut more aggressively during the early stages of sharpening.

Even though the loose abrasive increases cutting speed, it still produces shallower scratches than diamond plates.

At this stage, my goal isn’t to create a finished edge. Instead, I want to remove the deep diamond scratches as efficiently as possible before progressing through the finer Chosera stones.

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Chosera 400 Grit

Scrubbing with Slurry

The slurry creates a cloudy surface under the microscope, making it difficult to see exactly what’s happening beneath the paste. While the finish appears somewhat rough, much of the remaining texture comes from the slurry itself.

Sweeping with Slurry

After switching to sweeping strokes, the bevel becomes noticeably smoother than the finish left by the diamond stones. However, the very edge still appears somewhat toothy because the loose abrasive in the slurry creates a more aggressive finish.

If my goal were to stop at the 400 grit, I would sharpen without slurry to produce a cleaner final edge.

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Chosera 600 Grit

The 600 Chosera was used with water only.

Scrubbing

The 600 grit quickly replaces the remaining 400-grit scratches while producing a more consistent bevel.

Sweeping

By this point, the diamond scratches are essentially gone, leaving only the Chosera scratch pattern behind.

Although the 400 and 600 Chosera stones perform similarly, I find that the 600 grit provides a smoother sharpening experience and is the stone I personally reach for more often.

Generally speaking:

• 400 Chosera works well on softer steels.
• 600 Chosera performs especially well on harder steels.

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Chosera 800 Grit

The 800 Chosera provides an excellent transition from the Wicked Edge 600-grit diamond plate.

Since this knife had already passed through the Chosera 600, only water was used.

Under the microscope, the edge closely resembles the finish produced by the 600-grit diamond plate, but the bevel itself is noticeably cleaner and more reflective due to the polishing action of the Chosera stone.

At this stage, the knife already has a practical working edge suitable for everyday cutting.

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Understanding Slurry vs. Paste

It’s important to distinguish between slurry and paste when using Chosera stones.

Slurry

Slurry consists of loose abrasive particles released intentionally by rubbing two stones together.

It increases cutting speed and is best reserved for the coarser stones. I generally do not use slurry beyond the 1,000 grit level.

Paste

Paste is the dark buildup that naturally develops during sharpening. It contains:

• Water
• Steel particles
• Broken abrasive particles
• Small amounts of binder material

Unlike slurry, paste is beneficial.

It acts like a finer abrasive, polishing the scratch pattern while refining the apex beyond what the nominal grit rating might suggest.

Keeping the paste slightly wet allows it to remain on the stone and continue polishing effectively throughout the sharpening session.

The scrubbing strokes create the paste, while the sweeping strokes take advantage of it to produce a finer finish.

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Chosera 1,000 Grit

The 1K Chosera is one of my favorite stones for producing a practical working edge.

Its green color has earned it the nickname “The Incredible Hulk.”

The microscope images show a smooth bevel and a clean apex, thanks largely to the polishing effect created by the paste.

For many knives, this grit alone provides an excellent balance between cutting performance and durability.

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Chosera 2,000 Grit

Although the microscope images may appear slightly rougher than those from the 1K stone, the edge actually comes to a finer apex.

The resulting finish is comparable to the Wicked Edge 1,600 ceramic stone, while producing an even cleaner bevel.

Many sharpeners consider the 2K Chosera to be one of the best all-around finishing stones because it combines refinement with excellent cutting performance.

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Chosera 3,000 Grit

As refinement continues, deeper scratches left by earlier stones become easier to see.

This is completely normal.

Every sharpening progression eventually exposes the remaining scratches from previous grits before removing them.

Compared with the 2K stone, the 3K Chosera produces:

• A thinner apex
• A smoother bevel
• Increased surface reflection

As the surface becomes smoother, it begins reflecting more blue tones under the microscope. Eventually, as refinement continues, that reflection transitions toward white, indicating a highly polished surface.

Like the relationship between the 400 and 600 stones:

• 2K Chosera is slightly softer and more forgiving.
• 3K Chosera is slightly harder and often performs better on softer steels.

Both stones transition cleanly into the 5K grit.

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Chosera 5,000 Grit

At 5,000 grit, the scrubbing strokes clearly reveal the remaining scratch pattern while the sweeping strokes create a much smoother bevel.

To the naked eye, the bevel already appears fully mirrored.

Under magnification, however, the remaining scratches are still visible, showing that further refinement is possible.

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The Critical Leap

Every sharpening progression reaches a point where the scratch pattern becomes fine enough for the surface to reflect light uniformly.

I refer to this transition as the critical leap.

On the Chosera progression, a visible mirror finish appears to the naked eye by approximately 2,000 grit, but under the microscope the surface still contains enough scratches to scatter light.

The true critical leap occurs between the 5,000 and 10,000 grit Chosera stones.

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Chosera 10,000 Grit

At the final polishing stage, the 10K Chosera requires more strokes than the lower grits because the abrasive is removing such a small amount of material.

The paste produced by the stone leaves the bevel with an appearance that may seem slightly irregular under magnification, yet the bevel itself reflects like a mirror.

The remaining microscopic texture creates an edge that still retains a small amount of bite while delivering a highly refined finish.

From here, the edge is fully capable of shaving. If even greater refinement is desired, it can be followed with stropping compounds or additional polishing stones such as the Shapton series.

The Chosera progression demonstrates how water stones refine an edge differently from diamond plates. Rather than simply reducing scratch size, they also polish the scratch pattern, producing a combination of sharpness, refinement, and cutting performance that has made the Chosera series a favorite among many guided sharpening enthusiasts.