Abstract

An alternative to the normal dyeing route to achieving colour in leather is to exploit the chemistry of creating the natural skin and hair pigments, melanins. 1,8-dihydroxynaphthalene and other dihydroxynaphthalenes can be oxidised and polymerised to create pigment products by reactions catalysed by laccase, a polyphenol oxidase. They not only create colour, but, if the reactions are conducted in the presence of collagen, the pigments are bound to the collagen by covalent bonds, which confer a tanning effect.