I've seen posts here and there that talk about a BBS shave "lasting" longer with one razor over another, one blade over another etc.
Sorry, I'm not buying it.
First let us address the ability of each of us to "feel" the stubble after a shave.
The ability of humans to detect surface roughness with fingertips has been studied ad infinitum. The results are that in general humans are capable of determining relative roughness of a surface with the fingers to a significant degree - with caveats.
The caveats are that the ability to determine whether one thing is smoother than another is significantly affected by two factors:
1. The amount of pressure used during the "feeling" stage.
Even slightly different pressure levels causes the fingers skin contact surface to change. A slight increase in pressure causes more surface contact which increases tactile feedback. This means that a person who presses slightly more on a surface may, in error, think the surface is rougher, when in fact it is not.
2. The quantity and viscosity of lubricants present on the surface being felt.
Lubricants decrease the ability of the fingers to detect changes in surface roughness significantly. Lubricants may include moisture either applied or secreted as sweat, sebum (the skins "natural" oil), applied chemicals such as aftershaves or balms, and surface contaminants which are deposited on the face from the surrounding atmosphere.
In order to determine whether your skin feels rougher or smoother over a 6, 8 ,10 or 12 hour period, one would have to exactly duplicate the conditions that existed when the shave was completed and first felt by the individual, including:
1. The exact pressure used when feeling the face.
We are not machines, so this is not 100% repeatable. Moreover, studies have shown that even with people trained to apply a given pressure when feeling surfaces, that pressure is increased subconsciously the longer the feeling period is extended.
2. The exact same exertion level and physical status, which could produce sweat even in the slightest amount.
From day to day, even from hour to hour our reaction to physical exertion, no matter how slight, differs significantly.
3. The exact same environmental conditions over that time frame.
Unless one lives in a laboratory clean room, air quality changes constantly, and the skin is exposed to various environmental conditions such as humidity changes, pollens/microbial contaminants, and other particulate matter.
4. The exact same level of sebum production from the sebaceous glands.
The skin produces sebum, and though peak is during the teen years, even daily sebum production is affected by numerous factors including diet, level of physical activity, and exposure to environmental contaminates.
Next let us address the stubble being felt itself.
When facial hair is cut, there are only 3 options:
1. The hair is cut, to some varying degree above the skin surface.
2. The hair is cut perfectly even with the skin surface.
3. The hair is cut, to some varying degree below the skin surface.
On average, human facial hair grows approximately .27mm in 24 hours. As with all things - each individual may differ slightly on the plus or minus side. For the sake of the discussion, let us assume that in general, the same persons hair growth rate will not significantly change day to day, though it may change very very slightly due to factors such as fatigue.
If the hair is cut at some measurable distance above the skin surface, it is felt almost immediately, and for the sake of this discussion, is out of the equation.
If the hair is cut perfectly at the surface, and all of the above factors of lubrication and pressure are removed, the stubble will be "felt" at the same time period consistently. As mentioned, the factors of lubrication and pressure cannot be controlled to any degree.
If the hair is cut at some level below the skin surface, the hair must grow to a level even with, then above the skin level to be felt.
How much above the skin level it must grow to in order to be felt is again affected by the factors of lubrication and pressure.
Stretching of the skin, and the aggressiveness of the shaving process both have some effect on whether the hair is cut below the surface, and to what degree. However, the significant factors of lubrication and pressure again will bias what we perceive to be the relative smoothness of the shave.
In short, I think that those who experience what they believe to be a longer lasting BBS shave are influenced by the incontrollable factors mentioned above, combined with cutting of the hair below the surface of the skin to some degree. Regardless of which razor or blade is used, the blade will cut the hair at the level that skin stretching and shaving aggressiveness permits, not by virtue of the particular razor or the blade used.
That's my story, and I'm sticking to it.
Sorry, I'm not buying it.
First let us address the ability of each of us to "feel" the stubble after a shave.
The ability of humans to detect surface roughness with fingertips has been studied ad infinitum. The results are that in general humans are capable of determining relative roughness of a surface with the fingers to a significant degree - with caveats.
The caveats are that the ability to determine whether one thing is smoother than another is significantly affected by two factors:
1. The amount of pressure used during the "feeling" stage.
Even slightly different pressure levels causes the fingers skin contact surface to change. A slight increase in pressure causes more surface contact which increases tactile feedback. This means that a person who presses slightly more on a surface may, in error, think the surface is rougher, when in fact it is not.
2. The quantity and viscosity of lubricants present on the surface being felt.
Lubricants decrease the ability of the fingers to detect changes in surface roughness significantly. Lubricants may include moisture either applied or secreted as sweat, sebum (the skins "natural" oil), applied chemicals such as aftershaves or balms, and surface contaminants which are deposited on the face from the surrounding atmosphere.
In order to determine whether your skin feels rougher or smoother over a 6, 8 ,10 or 12 hour period, one would have to exactly duplicate the conditions that existed when the shave was completed and first felt by the individual, including:
1. The exact pressure used when feeling the face.
We are not machines, so this is not 100% repeatable. Moreover, studies have shown that even with people trained to apply a given pressure when feeling surfaces, that pressure is increased subconsciously the longer the feeling period is extended.
2. The exact same exertion level and physical status, which could produce sweat even in the slightest amount.
From day to day, even from hour to hour our reaction to physical exertion, no matter how slight, differs significantly.
3. The exact same environmental conditions over that time frame.
Unless one lives in a laboratory clean room, air quality changes constantly, and the skin is exposed to various environmental conditions such as humidity changes, pollens/microbial contaminants, and other particulate matter.
4. The exact same level of sebum production from the sebaceous glands.
The skin produces sebum, and though peak is during the teen years, even daily sebum production is affected by numerous factors including diet, level of physical activity, and exposure to environmental contaminates.
Next let us address the stubble being felt itself.
When facial hair is cut, there are only 3 options:
1. The hair is cut, to some varying degree above the skin surface.
2. The hair is cut perfectly even with the skin surface.
3. The hair is cut, to some varying degree below the skin surface.
On average, human facial hair grows approximately .27mm in 24 hours. As with all things - each individual may differ slightly on the plus or minus side. For the sake of the discussion, let us assume that in general, the same persons hair growth rate will not significantly change day to day, though it may change very very slightly due to factors such as fatigue.
If the hair is cut at some measurable distance above the skin surface, it is felt almost immediately, and for the sake of this discussion, is out of the equation.
If the hair is cut perfectly at the surface, and all of the above factors of lubrication and pressure are removed, the stubble will be "felt" at the same time period consistently. As mentioned, the factors of lubrication and pressure cannot be controlled to any degree.
If the hair is cut at some level below the skin surface, the hair must grow to a level even with, then above the skin level to be felt.
How much above the skin level it must grow to in order to be felt is again affected by the factors of lubrication and pressure.
Stretching of the skin, and the aggressiveness of the shaving process both have some effect on whether the hair is cut below the surface, and to what degree. However, the significant factors of lubrication and pressure again will bias what we perceive to be the relative smoothness of the shave.
In short, I think that those who experience what they believe to be a longer lasting BBS shave are influenced by the incontrollable factors mentioned above, combined with cutting of the hair below the surface of the skin to some degree. Regardless of which razor or blade is used, the blade will cut the hair at the level that skin stretching and shaving aggressiveness permits, not by virtue of the particular razor or the blade used.
That's my story, and I'm sticking to it.