Tanning is the process of treating animal skin with the aim of producing treated leather with increased durability and probably color, suitable for the manufacture of clothing, footwear, etc. The facilities where the treatment is carried out are called tanneries. The treatment process involves permanently changing the protein structure of the leather using appropriate chemicals such as tannins. Before the chemical treatment, the skin is depilated, fat is removed and left to soak in salt water from 6 hours to 2 days. Tanneries over the centuries were located on the outskirts of cities and outside residential areas as they are accompanied by an unpleasant smell.

In Greece, tanneries were also called "tabakika", a word that comes from the Turkish language.[1]

History

Treated hides in a tannery in Morocco

Leather processing in the tannery of the Hydrokinesis Museum in Dimitsana
The Greek word tanning is compound and comes from the Ancient Greek noun "byrsa" meaning "animal skin", and the verb "defo" meaning "to soften something with the hands".[2] Tanning is believed to have been practiced as early as 7000-3000 BC. in India[3], while there are written reports from Theophrastus who was also the first to attempt to record and scientifically understand the process.[4]

The procedure followed in ancient times was as follows: the skins arrived at the tannery dry and soiled. Initially, they were soaked in water to clean and soften, while they were rubbed to remove fat and flesh residue. The tanner then had to remove the hair. This was done by smearing the skin with some alkaline substance or simply by leaving the skin for many months, which also caused rot. The skins were then soaked in salt water and the hair, which had meanwhile loosened, was removed with knives. After the hair was removed, the tanner softened the hide by rubbing manure on it or soaking the hide in a solution of animal entrails. The above process was a form of fermentation involving the enzymes of the bacteria contained in the manure.

In later centuries, tanneries of vegetable origin such as cedar oil, oak bark, alum were used in tanning, which were spread on the skins while they were stretched, resulting in them absorbing more tannins and dehydrating.

After the Industrial Revolution and specifically after 1840, trivalent chromium solutions were used in tanning to soak the hides.

Tanning barrel at the Leather Museum in Igualada
Tobacco in Greece
From the 19th century until 1980, tanning played a special role in the economy of Greece. Large tanning centers developed in the Aegean islands (Syros, Chios, Samos, Rhodes, Lesvos), in mainland Greece (Larissa, Tripoli, Ioannina, Amfissa, Pelion: Makrinitsa - Koukourava). The Greek tanneries specialized in solo leather, therefore the appearance of rubber in the soles of shoes and in the belts of machines signaled the decline of Greek tanning.

Chios
Tanning in Chios has been flourishing since the beginning of the 19th century, when there were around 18 tanneries. The destruction of Chios by the Turks in 1822 forced several families of tanners to move to islands of the Cyclades such as Syros, taking their art with them. The union of the tanners of Chios with the name "Union of Tanners of Chios" was particularly strong and was founded in 1918, after the liberation.[5] Due to the role of Chios as a commercial center the industrialization of tanning took place quite early. In a first stage (before the First World War), equipment was acquired for the partial automation of the process (mechanical rotating barrels, mechanical hammers) while in a second stage chrome tanning was adopted which accelerated the tanning process to 3-4 days. During the Second World War, the stock of Chiot's buckskins was allocated for the needs of the Greek army, while the rest were seized by the Germans. In 1960, Chios produced 20-25% of all Greek sole leather, while after the 1960s it expanded into the production of re-leather.[6]

Syros
The tanneries of Syros were located in Ermoupoli, in the southern part of the port and were traditionally two-storeyed. The first tannery was founded by Chiotis Kaloutas in 1829. The second tannery was founded by the Cretan Saloustro in 1834 and was housed in Mandilara Street. In 1851, 12 tanneries are listed, while Syrian tanneries have displaced French tanneries from the market of the Ottoman Empire.