Porosity is the ability of the hair to absorb water and other
matter (like chemicals). In the post ‘Balancing Moisture &
Protein’, i gave a brief summery of what hair is. The outer
layer of the hair, the Cuticle, is made up of several layers of
interlocking scales and is responsible for how porous the hair
is. Different Degrees of Porosity Low or poor porosity is
characterised by very tightly closed cuticles and is generally
considered healthy as all or most of the cuticle layer is
intact. It doesn’t easily absorb water and resists the
penetration of chemical treatments. Normal Porosity is hair that
is able to absorb water well but resists permitting too much
water to penetrate. This is considered the best porosity to
have. Again, all or most of the cuticle layer is in tact and
lies down flatly. Hair with normal porosity can hold styles well
and receives chemical processing well. Although chemical
processes can change the porosity of the hair from average to
high. Highly porous hair is hair that has sustained