I actually have a pair of nice black boots where the dye is sort of a thin layer on top which slowly rubs off on the toes and heels. It looks real cool. But I've never seen it anywhere else.
On boots that can happen where it is a thinner, cheaper leather that is layered (as opposed to the top layers of hide for fancy dress shoes). It will be a blue colour underneath, where the dye isn’t in very deep, no?
I actually have a pair of nice black boots where the dye is sort of a thin layer on top which slowly rubs off on the toes and heels. It looks real cool. But I've never seen it anywhere else.