A tannery is the works where raw hides become leather. The people who work there are tanners. A tannery is not a tanning salon, and it is not a factory that makes bags or belts. Those are leather goods makers.
Tannery, tanner, or leather worker?
- Tannery: the site where hides and skins are processed into leather.
- Tanner: a person who works in a tannery.
- Leather worker or leathercrafter: a person who cuts and assembles leather into goods such as bags, belts and saddles.
Some older trades also shaped the vocabulary:
- Currier: a craftsman who dressed and oiled vegetable-tanned leather.
- Fellmonger: a trade that removed wool from sheepskins.
- Tawer: a worker who made alum-tawed leather.
Inside a tannery
A tannery is usually organised into three areas:
- The beamhouse, where hides are soaked, limed, fleshed and split. This is where the hair comes off.
- The tanyard, where hides are tanned. Chrome tanning happens in large drums, and vegetable tanneries may also use pits.
- Post-tanning and finishing, where leather is retanned, dyed, dried, softened and finished.
Typical equipment includes:
- rotating drums, made of wood, stainless steel or polypropylene
- fleshing machines and band-knife splitters
- shaving machines
- sammying and setting-out machines
- vacuum and toggle dryers
- staking machines
- spray lines
- plating and embossing presses
The stages are described in how leather is made.
Tanneries specialise
Not every tannery does everything. Some sell wet blue, which is chrome-tanned leather that has not been dyed or finished. Others sell crust, which is tanned, retanned and dyed but not finished. Some sell fully finished leather. Many tanneries buy semi-processed leather rather than raw hides.
Where tanneries are
Tanneries cluster in a few regions. Well-known examples include:
- Arzignano, Italy, a hub for chrome tanning
- Santa Croce sull’Arno, in Tuscany, home to a vegetable-tanning consortium
- León, Mexico
- Kanpur, and the Vellore and Ambur areas, India
- Savar, Bangladesh, where tanneries were relocated from Hazaribagh starting in 2017
- Fez, Morocco, where the medieval Chouara tannery still operates
Large producers by volume include China, Brazil, India and Italy, though rankings shift from year to year.
Tanneries were traditionally built outside towns and beside rivers, because of the smell and the amount of water they need.
Water, effluent and certification
Tanning uses a lot of water. Historically cited figures are about 25 to 40 cubic metres per tonne of raw hide, and modern plants use less. Figures vary.
Wastewater can contain chromium, sulfides and other chemicals. How much a tannery pollutes depends on its effluent treatment and chrome recovery, which vary widely by region and by rules. Not every tannery pollutes. But poorly regulated clusters have been documented with chromium water pollution and illness among workers. Kanpur and Hazaribagh (before 2017) are commonly cited examples. The chemical side of this is covered in is chrome-tanned leather toxic?.
The Leather Working Group (LWG) audits tanneries’ environmental performance and grades them Gold, Silver, Bronze or Audited. A grade reflects environmental practice. It isn’t a guarantee of every chemical in the finished leather.
Working in a tannery
Tannery work carries real hazards. Sulfide liquors release hydrogen sulfide gas, lime is caustic, and chemical dust is a risk. Workers rely on protective equipment and ventilation.
Common misconceptions
- A tannery is not a tanning salon, and it is not a leather goods factory.
- Not every tannery handles raw hides or every stage.
- Not every tannery pollutes. Effluent treatment varies a lot.
For how tanning times compare across methods, see how long it takes to tan leather. For the traditional tanneries that still work by older methods, see traditional leather making.