How has the tanning of leather for footwear evolved over the centuries?
During the Renaissance, the tannery underwent a great revival in Spain, particularly in Cordoba, Granada and Barcelona, in Italy with the schools of Venice and Florence which honored the manufacture of golden and silver leather.
In France, mainly in Châteaudun, Orléans, Paris and in the Lyon region, the leather trades took on considerable importance and the profession was very prosperous in the 16th and 17th centuries.
However, the transformation processes remain empirical, and the tools rudimentary (scrapers, knives, etc.). In France, the number of tanning workshops is estimated at around 5,000, employing 30,000 to 40,000 people. Each city or town then had one or more tan mills attached to a tannery. Around 1710, Colbert commissioned a census which was to be the origin of the establishment by Louis XV of professional statutes around 1734.
Between 1762 and 1764, de Lalande had his work “L’Art du Tanneur” published. Diderot’s encyclopedia evokes the profession from 1790 in his encyclopedia.
At that time, leather was mainly used for footwear, bookbinding and for horses.
In the 18th century The Revolution, which needed leather for the armies of the North and which could only note the slowness of the manufacture of leather (about 18 months), asked Mr. Seguin, a renowned chemist to find a faster method. . He thus developed a process by extraction of the tannin contained in the bark, the first of its kind. But the leathers produced are of poor quality and Seguin barely saves his head. It is only a century later that the extraction processes will be perfectly mastered!
Some chronicles dating from 1793 recount attempts at tanning human skin which, of course, had no follow-up, although the thing caused a sensation at the time.
In the 19th century and at the beginning of the 20th century, chrome tanning was discovered in 1850 by the German chemist Knapp, but it was not applied until 1883, according to the experience of the American chemist A. Schulz. His discovery served as the basis for chrome tanning. The industrial development of tanning with trivalent chromium sulphate enabled the development of an industry considered strategic, in the very first half of the 20th century.
The first vegetable tanning extracts were industrially produced in France from 1870.
The first machines to facilitate work appeared between 1880 and 1890.
At the start of the 20th century, the French leather industry was considered the third largest industry, after metallurgy and textiles.
In 1905, the tannery alone brought together nearly 1,500 companies employing 25 to 30,000 people. It should be noted that raw skins have been purchased since 1859 at public auctions, whose statutes are still in effect. Between 1910 and 1945, there were certainly technical improvements and the creation of new machines, but progress was very limited. The manufacturing cycle remains long, from 6 to 18 months, and the tanners must have a lot of capital to build up the essential stocks.
From 1950, modern processes associated with machines gradually supplanted the old methods with the corollary of an increase in productivity and the diversity of the leathers produced. Great upheavals intervene which completely modify the traditional aspect of the companies. Abandoning the artisanal sector, the majority of companies actually integrate the industrial sector, characterized by large production volumes, perfectly adapted machines and better and better controlled processes.
The development of chemistry allows the use of new processes and to obtain an increasingly wide range of leathers. The leather industry thus took advantage of the appearance of synthetic polymers to develop finishing techniques. It can then follow fashion and provide leathers with increasingly varied aspects:
- Modern with iridescent reflections
We also tan new types of skins:
Parallel to the development of chemistry (tannins, dyes, polymers), it is necessary to announce the considerable progress made in the material of tannery. The industrial era is revolutionizing this “craft”. Tanning which was static, in the pit, becomes dynamic and much faster with the appearance of the fuller (large horizontal cylinder rotating on its axis).
At the same time, consideration of the environment intensified, particularly from the 1970s.
In a few decades, the age-old preponderance of vegetable tanning diminished and, for leather uppers (shoe uppers) for example, the new chrome tanning method almost completely replaced the old process.
The uses of leather are changing, with in particular the sharp reduction in leather for industrial use (belts, gaskets, etc.). The French tannery specializes in the manufacture of leather for shoe uppers and no longer just sole leather, then more recently (from the 1980s) has turned towards the manufacture of leather for leather goods, mainly high-end.