The next step was the 1 micron boron carbide on top grain cow leather:


1 Micron Boron Carbide Top Grain Cow Leather

Here the burnishing and polishing seem pretty clear. All the fine little ridges are flattened out, reducing the light scattering and allowing us to see the deep scratches. I put on a polarizing filter because so much light was now reflecting back into the lens. In retrospect, I wish I'd done a step at this point with clean, top grain cow leather. Maybe even before the split grain horse butt leather. I'm taking notes for a future progression as these questions come up.

I've got some emails and calls to answer, but I'll come back and continue once I can break free.

LukasPop wrote:


I think that's a great next step. Most likely, I'd try to divide the cutting tests into at least two categories; push-cut and slice.

mark76 wrote:


This is where the progression is flawed because I used the horse butt leather for the .25/.125 and cow leather for the 5/3.5 strops. I wish now I'd used the cow leather for both! I think the biggest difference we're seeing is in the leather itself. Clearly I'm going to have to repeat some of this using the same leather (ideally from the same lot) to do the entire progression. One thing that seems easy enough to see is the increasingly larger scratches as I descended back down the ladder from 3.5> 5> 10> 14.

razoredgeknives wrote:


Here are some pictures of my 100 grit stones compared with some new 100 grit stones:


Used 100 Grit - Not polarized


Used 100 Grit - Polarized


New 100 Grit - Not polarized


New 100 Grit - Polarized

On the new stones, what you're seeing are all the diamonds that have yet to be knocked of. Until those are gone, you won't even be able to see the layer below. All the extra diamonds dig much deeper scratches and the edge you get is significantly more toothy until the stones are broken in. The same is true with all the diamond stones. I think that's why I was able to move from grit to grit so quickly and end up with such a nice result. Another progression to do: New 100 grit> Old 100 grit> New 200 grit> Old 200 grit> New 400 grit> Old 400 grit etc...!

Very clear, Clay. Thanks!

I guess I'll do some experiments myself using the WEPS strops, that feel very smooth. They are clearly top grain leather. Are they cow leather?

mark76 wrote:


They are cow leather. I'd love to see your results once you get some experiments done.