IMGR20

Chapter Three

DRESSING THE SKINS

[(bas noc pcevioajły been madę elear chat, in ia origins, che story of ‘Spanish’ leather bad m do with one of the three basie methods of converting iaw hides and skins into leather’ - che one now known as the 'minerał process’. Ic may be helpful to acplain that npto the close of the nineteenth ccntury there were three fimdamentally iffeent ways of making leather, the products of which differed greatly one from anocher I their charicteristicł.

The fot, and perhaps the most impoctanc, is Tarning_t a term ofien uscd looscly. ttiedy it is applicable only to the vcgctablc process which employs the 'tannin* (tannic ud) ptesent in varying degtee in all vegctable matter to bring about a permanent change i the naturę of the collagen contcnt of hides and skins. The csscntial difference betwcen iw skin and vegetablc-tanned leather is indicated by the face that wheieas the former iay be dissolvcd in hot water (making glue or size), and in conditions of dry beat may aohre into a treacly mass as, for example, Carter found had happencd to the rawhide nesh flóors of Tut-ankh-amun’s chariots, the tanned product remains demonstrably aihcr after repeated or cvcn prolongcd wettings, as witness the many leather objects ecovcred from rivers and bogs that have been softened but otherwise little harmed. leather will hcat greatly harm it. Fungoid growths and sulphur dioxide provide the chief lazards.

The iccond method, known in mediami times as Cbatnoising, is an oil oxidation nocas, employing marinę ani mai or fish oils such as cod-liver-oil, in which hcat can be pnetated under pressure. This produces a kind of leather exemplificd by what is called wash-łeatha’ (or ‘thammy’), and a leather now rarc but still familiar to the last generation is *bufT (becausc sotneume madę from buffalo hide) which gave its name to the pale icflow colour so dcsignaicd.

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