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Is it BBS? An experiment from Philips Research Laboratories in 2004

pdf file: The smoothness of shaven beards: The relation between stubble length distribution and skin parameters and tactile smoothness

Synopsis
In this report we describe how the tactile smoothness of shaven beards depends on the distribution of the stubble lengths remaining after shaving and on various skin parameters like coarseness and scaliness.

In other words, they measured what different people mean by BBS.

Thus we would like to summarize our main conclusions from both experiments as follows:
  • There are individual differences among normal, untrained people in judging tactile smoothness, specifically in the smoothness criteria they use. Nevertheless, we can discern a more or less common general line.
  • The higher the average length and the density of stubble hairs, the lower the perceived smoothness. Specifically, we find that a reduction of 1 hair/cm[sup]2[/sup] in hair density yields the same improvement in tactile smoothness as when L (length) decreases some 6 microns.
  • The orientation of the stubble influences perceived smoothness such that if the hairs are oriented vertically in the plane of the skin surface (usually against beard growth), tactile smoothness is lower.
  • There is some, not fully understood, evidence that skin quality is an influence on smoothness perception.
 
Awesome and ridiculous. My previous job was in a food canning plant. One of the products we made was "Potted Meat Food Product". Yep - awesome.

One day, my workers accidentally added a bit too much vinegar to the batch. So everyone came in to taste to see if they could detect something wrong. Yep, they sure did; everyone thought it tasted funny. Do you know why? None of the people that came in to taste it had ever eaten the product. It has TRIPE (and some other lesser used meats) in it. If you've never eaten Potted Meat Food Product, you'll think it tastes funny.

What is my point?

If you ask an untrained person what they think about something they've never thought about...they'll have no idea what they're talking about.
 
Started to read the wiki. A lot of interesting things in it. The cold water shavers, however, may want equal time in the discussion of temperature in which the beard softens. :lol:
 
pdf file:
Specifically, we find that a reduction of 1 hair/cm2 in hair density yields the same improvement in tactile smoothness as when L (length) decreases some 6 microns.

If I read this right, I could just pluck 1 hair out of cm2 and that would yield the same smoothness as 1 pass with a blade.

Sure it would. :001_rolle
 
If I read this right, I could just pluck 1 hair out of cm2 and that would yield the same smoothness as 1 pass with a blade.

Sure it would. :001_rolle
Doing the math...

Hair grows about 1/2" / month
= 12 mm /month
= 0.4 mm / day
= 400 um / day
= 16 um / hour

So 6 um is about 22 minutes of growth.

If each pass is supposed to remove the same length of hair (which we all know isn't consistent across passes), then for a daily 4 pass shave, each pass removes 100 um. That 6 um is only 1/16 of a pass.

Or... In terms of smoothness, each pass removes 16 hairs / cm[sup]2[/sup].

I was half expecting to put a winky smile here, but it actually seems plausible. Anyone want to count the hairs in a cm[sup]2[/sup]? This suggests an average of 64. This suggests a standard way to calculate hair density. We could find something with a 1 cm[sup]2[/sup] hole, tape in on our face, take a picture, and have a survey. (Whatever we use doesn't actually have to be 1 cm[sup]2[/sup]. We just need to find something readily available, and adjust the number.) I can almost imagine Badger & Blade as the ISO standard setting organization for beards. We'll make P&G and Schick play ball. :wink:

And someone please check my math. I'm still groggy having morning coffee.
 
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