Jul 15, 2022 6 min read

While working as a wildlife officer, I was required to pick up road-killed deer and then dispose of them. However, during the fall I was to salt the deer hides and stack them in a shed to be saved until winter. We would then receive instructions on where to take the stored hides.

At this location, the commission would sell the hides to a tannery, with the monies going into the game fund. This was a dirty and smelly job, and not one that I looked forward to doing. Today, hunters and trappers can still sell their deer hides to local buyers that deal with tanneries.

Tanneries, which were once familiar landmarks in almost all sizable communities, have disappeared from the American scene. The knowledge and skill of the old time tanners has also vanished. Tanneries were always built on the outskirts of a community due to their foul smells.

The history of tanning goes back to the very origin of civilization. For thousands of years, man has known how to preserve the skins of animals by making them soft and pliable. Egyptian leather specimens, which are more than 3,000 years old, have been found in almost a perfect state. The Babylonians also made leather and the Hebrews discovered a tanning process that is still in use today. The principal leather still made by ancient methods is called chamois leather. Today we wash windows and cars with a chamois cloth.

The Romans used leather and tanned skins as a basis for money.

Our American Indians piled deerskins so that the tissue surrounding the hair rotted off. The flesh was then scraped from the inner side of the skins and hides were tanned by pounding oil, brains of animals and wood ashes into the skins. Next the hides were allowed to dry and lastly smoked over a fire. This process produced a soft leather that the Native Americans called buckskin. The slang word buck, which is used for a dollar bill, comes from the fact that deer hides were at one time used for money.

While all animal skins can be tanned, the hides from cattle, sheep, goats, pigs and horses are the most important for making leather. Cattle hides are mainly used in the making of leather for shoes, clothing, luggage and upholstery.

Most animal skins are cured to prevent spoilage before going to a tannery. After arriving at the tannery, the hides are soaked in water to soften and remove any substance that could have been used as a preserving agent. After the soaking operation, the hides are washed to remove dirt and foreign matter.

The skins are then placed in a machine that removes the flesh and tissue from the inner side of the skin. Next the hides go to the beam room, where they are treated to remove the hair. The hides are then soaked in a vat of a solution of lime and sodium sulfide for three to seven days. At the end of this period, the hair is easily removed and saved, washed, dried and used for making felt, coarse blankets and other articles.

Today, in some tanneries, the hair is chemically dissolved.

The lime solution swells the hides, making it necessary for them to be re-fleshed. The hides are then scudded, removing the last bit of skin and hair roots. This scudding is usually performed by hand, with a moon shaped knife.

After the hides are washed again, they are soaked in a neutralizing agent such as ammonium sulfate or chloride. This operation is known as bating. In the past these enzymes were provided by dung from dogs, chickens and pigeons. Today bating is provided by finely divided pancreas.

From here, the hides go into either a vegetable or a mineral tanning, depending on what the leather is to be used for.

Leather for shoes, bags, upholstery, harnesses and belts, go through a vegetable tanning. In the past, this process was known as bark tanning because practically all the leather was tanned with an extract of a specific bark. All vegetation contains a bitter ingredient called tannin. This tannin is removed from the plants by using hot water. Hemlock, oak and sumac are three of the main plants that tannin is derived from. The tanning combines with the proteins to form a compound that will not rot easily. Vegetable tanning produces a firm, heavy and water resistant leather.

The other tanning method is known as chrome tanning and is used chiefly for tanning the upper leather of shoes and handbags. It is not suitable for upholstery.

After the hides are bated and washed, in chrome tanning, they are pickled with a solution of acid and common salt. This pickling neutralizes the lime that can be present from the bating. The leather goes into a one or two-bath method, depending on what the leather is to be used for. A chrome-tanning produces soft elastic leather.

Following the tanning process, the leather is sorted, split and shaved to a uniform thickness. Now it is ready to be colored.

The leather is dyed with a number of aniline dyes and natural wood dyes. From two to seven different coloring materials are required to obtain a desired shade since it is nearly impossible to color leather with a single dye.

After coloring, the leather goes through a process known as fat liquoring, which ensures that the leather stays pliable and strong.

During this process, the leather is soaked in soap that is made of animal oil, mineral oil and vegetable oil for about an hour. The hide readily absorbs the oils and grease. The leather is dried and hung out to absorb moisture from the atmosphere. Next, the leather is dipped in warm water and placed into damp sawdust that absorbs approximately 35% of the moisture. The leather is then stretched onto metal frames where it is allowed to dry.

Finally the leather is given a finish, using many different items, such as shellac, milk, blood serum, flaxseed, pigments of all kinds, etc. As many as seven coats are applied to the finest of leather.

The high gloss of patent leather is produced by applying three coats of a heavy oil varnish at the end of the finishing process.

Suede leather is made from sheep or lamb skins, dressed on the flesh side, finished without glaze and then buffed to give a fine nap. Suede leather has little resistance to water. Cordovan leather, which is produced from sheep skins, is embossed or tooled and colored mainly scarlet. Cordovan leather is highly prized and its name comes from the Spanish city of Cordova, where it was first produced.

Imitation leather came into use during World War II due to the great demand for leather.