I discussed a leather store about the white border aka salt border on leather shoes. They said that it is due to inner features of leather and you could try to add some fat/cream to push it back inside the shoes. I haven't yet understood physiology of skin here, "why does it act like that?"
is the first doubt and then the second "does human skin act the same way?"
-- I can see this kind of salt borders in gym clothes when they cry uncleaned but haven't seen them yet on my skin at least. The extra salty water from legs causes real damage, such as getting the inner fluids out, to the leather. When you do heavy training, the salty sweat in the human skin acts apparently the same way. So:
how to manage the skin in living human skin and how does it differ from leather maintenance? What is the common physiological background with the different kinds of skins?
I try to answer it myself:
- leather: you can add the fat/cream/etc only externally
- living human ski: you can add the fat/cream-etc both internally (fatty food) and externally (lotions)