pdf file: The smoothness of shaven beards: The relation between stubble length distribution and skin parameters and tactile smoothness
In other words, they measured what different people mean by BBS.
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.