The value of a hide

Mike Redwood

Columnist

International Leather Maker

How do you go about assessing a hide or skin when it enters your tannery? What is on top of your mind?

When I joined the leather industry after leaving university, I was made Technical Director of a large UK leather tannery after only a year. Probably foolish overpromotion, but who would hesitate, and my only doubt was a weird request to shave off my beard.

My degree course was entitled ‘Leather Chemistry’, so although it added a year to a pure chemistry degree, it had none of the practical elements of a Reutlingen or London Leathersellers, instead extra work on bacteriology and rheology. We were taught very little about finishing, and as my vocational tannery work had all been in heavy vegetable leather tanneries, I was not well prepared for a large chrome tanned side leather production heavily sold as corrected grain for footwear articles.

I was in Hull, in a Barrow Hepburn tannery, with a historic vegetable plant on the same site, and while the chrome tanned shoe leather production was well established, its “newness” compared with the original plant meant there was still a cultural divide. The mindset for hide examination in raw and after hair removal, or in wet-blue, was very much how well the hides would fit the production expected of them.

With a high-volume throughput, my focus was on the weight range and defect classification. In the early stages, we worried about flay damage and warble fly, and the fit with existing drum recipes and other processes. The whole mindset was related to achieving production efficiency, inter- and intra-batch uniformity, specification compliance and cost per square foot.

This was very much an orientation toward repeatability and throughput rather than individualised hide optimisation. Detailed processes were established, changes required approval and efficiency metrics dominated. These were the days of work study.

Quite heavy retanning was required to get the leather to stand up well to buffing and impregnation, and these were all proprietary mixes from chemical suppliers who often tried to hide the contents, making the tannery technician dependent on the supplier. I could normally see through this, but the finishing was more complex as I had neither learned the chemistry nor the applications, and I was very dependent on good friends like Philip Rothwell from Stahl and John Attley from Quinn.

Brown haircell print

Our biggest customer was Clarks shoes and our major leather for them was a brown haircell print for children’s sandals. It was a leather of the moment and not of the future, which soon became obvious. But although he did make some softer, kinder leathers in full or semi-aniline, it was difficult as our equipment with paste-drying, through-feed buffing, curtain coating, padding and spraying, was all dedicated to efficient corrected and pigmented productions, and the staff were used to this.

Two years later, I found myself working in Santa Croce as an “overseas technician”. John Bird and his wife Paddy had invited my wife and I to dinner in York and to our surprise suggested a move to Italy. John knew I had been rejected after applying to manage a new Barrow Hepburn tannery in Brazil and argued that Santa Croce would be a unique opportunity that would better prepare me for managing tanneries around the world. He was certainly correct.

From my very first day it was quite clear that every Tuscan tanner and tannery worker, as far as I could tell, was looking at something quite different.

In Santa Croce sull’Arno, a tanner would acknowledge first the animal and its breed, region and husbandry and would then establish how he might unlock the maximum value of this specific hide. He would be reading the surface narrative, taking in any scars and the grain characteristics. The depth of the growth marks in neck, the looseness in the belly, and of course, the state of the grain.

Basso di fiore

They were not the first words of Italian I learned, but they should have been. The grain, or fiore in Italian, is the essence of the leather in Tuscany. The grain enamel is called the “basso di fiore” and is a gossamer-thin outer layer of the papillary dermis. When the hide is in its swollen, alkaline state, the delicate grain surface is at its most vulnerable. The uptake of water by the collagen forces the chains apart, destabilising the cross-links between them. In this condition, very little additional stress — excessive temperature, chemical attack, or mechanical abrasion — can cause those links to break, resulting in grain damage. Even moderately warm process liquors can be destructive.

If you intend to buff, pigment and plate as I had been used to, it has no relevance, but if you want to let the hide live its second life and tell its own story, it must be preserved.

To my new colleagues, this had to be protected at all costs. It is this that ensures the sparkle of the grain, the lustre and also the ability to accept an even finish. Basso di fiore describes the sad, matt, sometimes nubuck areas where the grain had been degraded.

What was very clear to me back in the Santa Croce of the 1970s was that the technicians had a high level of discretion based upon their visual judgement of the grain. As I worked through different areas of the many tanneries in the Rosati Group, workers at every level were willing to stop me and share their knowledge of how a small adaptation would ensure a better outcome. Somehow, I was involved in a very creative “imperfection management”.

This adjustment of liming time, shaving tolerance, retan choice and fatliquor selection were all subtly altered based on what that particular hide presents. At the centre of this approach is consideration of where we look for the value in the hide.

When I started in the UK side leather tannery, that value was always delivered within cost constraints that in the second half of the 20^th century were ever tightening until 300 tanneries were reduced to 30. But in Italy, the value is viewed from another perspective. Tanners viewed the true hide value as something that the hide had to be allowed to reveal.

Two profoundly different cognitive frames. One comes from a place with a long history, proud of its aesthetic innovation, pigment-minimising finish development working in an environment of closeness between the tannery and the finished product. They knew that each hide carries traces of an ecosystem—of trees, water and weather— and a husbandry approach.

They wanted that to be visible in the finished article via the grain appearance, which was to be authentic and honest, the transparency of an aniline finish and the patina that would keep that visible through time.

By comparison in the UK, I was located in a single large tanner making large footwear and leather goods production, emphasising scale, speed and specification compliance. The problem here is that leather’s value shifted from “dead animal transformed” to “technically sophisticated product”. Quality became legible through standards, specifications and testing. Yet this also created ‘opacity’: consumers could not directly assess the tanning quality, hide origin, or process integrity. This opacity opened the space for storytelling.

An emphasis on patina, ageing and full-grain “naturalness” within what is today an industrial system shows how Tuscany mastered how to convert leather into cultural capital, whereas not all, but much of the rest of the world has chosen to convert leather into manufacturing reliability, a commodity, and we are all paying the price today.

Fifty years on from first driving down the hill into Santa Croce, I have to recognise that there were lessons that I did not learn well enough.

mike@internationalleathermaker.com

You can find Dr Mike Redwood across social media at @michaelredwood.

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