article_snippet: Beard hairs are, on average, a tenth of a millimetre in diameter.
article_snippet: When dry, the hair is around 130 microns in diameter (left) but when hydrated this expands to almost 150 microns.
article_snippet: Beard hairs are, on average, a tenth of a millimetre in diameter.
article_snippet: When dry, the hair is around 130 microns but when hydrated this expands to almost 150 microns.