What does cutting paper do to an edge?

[WhiteRabbitAgain]

Across these threads I've seen it mentioned cutting paper as a test, and also that paper should not be used as a test.
I am wondering what the specific reasoning against it is.
My guess is that the tough fibers or materials in the paper will blunt the edge, or perhaps stick in the edge, but is this anything worse than what hair does, or anything that couldn't be remedied with regular stropping?

 

[Legion]

Cutting paper with a razor edge will dull it pretty much instantly, more than stropping will correct. Save that test for knives.

 

[rbscebu]

Yes, it is worse than what hair (whiskers) do and yes again, it does worst than what can be corrected by regular stropping. Paper is generally made of cellulose, the same as timber. Paper is about 100μm thick, while whiskers are about 20μm to 40μm thick.

It you have two identical SRs give it a try with one of them. You can then report back on B&B with your findings.

 

[Legion]

Yes, it is worse than what hair (whiskers) do and yes again, it does worst than what can be corrected by regular stropping. Paper is generally made of cellulose, the same as timber. Paper is about 100μm thick, while whiskers are about 20μm to 40μm thick.

It you have two identical SRs give it a try with one of them. You can then report back on B&B with your findings.

Or if you have one razor, hone it nice and sharp, then shave with it. Then cut some paper, and give it a good strop. On the next shave, tell us if you feel a difference.

 

[TSENG]

If it were me, I wouldn't test with "paper", but with soft "toilet paper".
After removing the "micro chips"or "burr", it will leave a vertex, creating a new smooth shaving edge, will not cut the toilet paper, reduce the damage to the skin, pass the edge test of your own habits, and shave smoothly.

 

[rbscebu]

If it were me, I wouldn't test with "paper", but with soft "toilet paper".
After removing the "micro chips"or "burr", it will leave a vertex, creating a new smooth shaving edge, will not cut the toilet paper, reduce the damage to the skin, pass the edge test of your own habits, and shave smoothly.

Toilet paper is just as bad as "normal" paper. Toilet paper is generally still made of cellulose fibres. It may feel soft on your skin becauise it is more flexible but to a SR edge it can still be just as harsh.

 

[TSENG]

Toilet paper is just as bad as "normal" paper. Toilet paper is generally still made of cellulose fibres. It may feel soft on your skin becauise it is more flexible but to a SR edge it can still be just as harsh.

I can't understand what you think, and I understand the way I choose.

 

[Legion]

Toilet paper is just as bad as "normal" paper. Toilet paper is generally still made of cellulose fibres. It may feel soft on your skin becauise it is more flexible but to a SR edge it can still be just as harsh.

I think what he is saying is that if it doesn't cut the TP, then the edge is more refined. Being that all the burrs are removed.

 

[JPO]

I tried this paper tissue/toilet paper test on a feather DE blade, and on an artist club blade. Both of these passes this test really well. It does not hurt the edge. Cutting into hard paper that is a different thing. So, it might be relevant to make some distinction here, because the type of paper makes a difference, and if, and how you cut into it factors in.
There are probably other tests that are less destructive to the edge, but this test works fine.

Reflecting the edge apex against an overhead light source gives you the same information. You can pick up things here which is difficult to see even under a microscope. It almost looks like dust particles that reflect light if there are some artifacts left on the edge.
Hair that is not properly hydrated has close to the same hardness as copper wire. Propper hydration helps allot, but a three-pass shave is probably much more demanding for the edge then a light touch on some tissue paper.

Micro chipping from the edge bending as it cuts the wiskers is the main wear mechanism for a razor blade, in addition to plastic deformation as the edge is pushed back.

 

[DrStrange]

I think what he is saying is that if it doesn't cut the TP, then the edge is more refined. Being that all the burrs are removed.

Going by that metric, the spine is more refined than the edge.

@Legion is saying that cutting paper ruins the edge.
@TSENG didn't follow.

The fact that cutting paper ruins the edge
is why some safety razor blades
are adhered to the center of their wrapper.

 

[TSENG]

I think what he is saying is that if it doesn't cut the TP, then the edge is more refined. Being that all the burrs are removed.

yes,Thanks.

 

[rbscebu]

I think what he is saying is that if it doesn't cut the TP, then the edge is more refined. Being that all the burrs are removed.

Thank you. I was misunderstanding him.

 

[WhiteRabbitAgain]

Hair that is not properly hydrated has close to the same hardness as copper wire. Propper hydration helps allot, but a three-pass shave is probably much more demanding for the edge then a light touch on some tissue paper.

Micro chipping from the edge bending as it cuts the wiskers is the main wear mechanism for a razor blade, in addition to plastic deformation as the edge is pushed back.

What factors affect hair hydration and what is the best course to keep it hydrated?

 

[RayClem]

As someone who spent his entire career working as an engineer in the paper manufacturing industry, I do not suggest using paper to test the edges of your razors. If is fine to use paper to test to see if the bevel is set properly to form an apex, but do not use paper to test your final edge.

Paper is made from a combination of hardwood and softwood fibers. Toilet paper is produced from softwood fibers. Although the basis weight (weight per unit area) of toilet paper is lower than some other types of paper, toilet paper is manufactured primarily from softwood fibers that are much larger than hardwood fibers.

Please do not use papers designed for use in printers and copiers. Although these papers tend to be higher in the percentage of smaller hardwood fibers, such papers contain fillers such as calcium carbonate, calcined clay and titanium dioxide to make the paper opaque. These fillers can be abrasive.

If you insist on using paper to test your razor edges on paper, I suggest using lens cleaning wipes, but not the ones that come pre-moistened. They will be more gentle that other types of paper.

 

[WhiteRabbitAgain]

Yes, it is worse than what hair (whiskers) do and yes again, it does worst than what can be corrected by regular stropping. Paper is generally made of cellulose, the same as timber. Paper is about 100μm thick, while whiskers are about 20μm to 40μm thick.

It you have two identical SRs give it a try with one of them. You can then report back on B&B with your findings.

I don't have two identical razors, but I have one that existed in two different points in time, so I tried that.
I have used it 5 or 6 times after honing it, it was as comfortable a shave as I have had.
I sliced the heck out of some paper, stropped it, and the subsequent shave was pretty bad. It shaved, but it was tuggy and didn't go as clean as usual.
It clearly dulled it, which I expected, what I am trying to understand is what is going on at that microscopic level that causes it to dull.

 

[kcb5150]

It's probably the clay among other things. I had more than one newb ruin fresh edges on straight razors they bought from me pulling them through printer paper and cardboard and then wondering why they were shaving poorly thinking that is how you "test sharpness." The paper thing is another knife guy habit that should never be mimicked by razor people.

 

[Titleist]

Rock, Paper Razor. A new variation for straight razor addicts.

Rock sharpens razor, razor cuts paper, paper dulls razor.

 

[JPO]

What factors affect hair hydration and what is the best course to keep it hydrated?

There is no simple answer to this. Strip away as much of the oil around the hair as possible. Stay away from pre shave oils. It only protects the skin, but will also reduces hydration.
Use a good soap/cream that can hold allot of water.

 

[rbscebu]

What factors affect hair hydration and what is the best course to keep it hydrated?

Read the instructions, particularly the section covering pre-shave preparation.

 

[RayClem]

What factors affect hair hydration and what is the best course to keep it hydrated?

In its natural state, hair is coated with oils that prevent water from penetrating the structure of the hairs. The first thing you have to do is use a soap or detergent to remove these oils. Once the hairs are clean, water will readily penetrate. This can be done with a hand soap, shaving lather, shampoo, liquid soaps, etc.

In its natural state (dry), beard hairs have a tensile strength of copper wire of similar diameter. When hair is hydrated, the fibers swell and the tensile strength drops significantly. This make shaving much easier, especially for those who have coarser beards.

As long as your shaving lather has a suitable ratio of water to soap (approximately 10:1), the lather will keep your beard hydrated throughout the shave. If you feel the lather is drying out during your shave, add a few drops extra water.