How Your Hide is Being Tanned - Leather in furniture (Part 1)

Leather is one of many types of coverings used in furniture today. Many people find this product to be both very comfortable and highly durable for everyday use in their homes. Exactly what is leather though and how does it make its way into your furniture? Why does it cost so much? To answer these questions objectively requires us knowing more about leather and in this three part article we’ll look at the stages that hides go through to become leather and how different qualities of leather hides are determined which can often affect the price you’ll see in furniture stores.

The basic definition of leather is that it is a material that is created through the tanning of raw hides primarily cattle hide. The interesting thing to note about leather is that it is a by-product of the meat industry which means that the meat is the primary value of the animal and the other raw materials like hides are of a secondary value. This is different than industries like fur where the fur is the primary value and the by-product is the meat. Raw hides cannot be used without processing as the skins arrive to the tannery in a cured form and must be returned to a state that involves reversing the curing process. Tanning is a generic term used in the leather industry to describe the process of converting raw hides or skins into leather which takes us into the beginning process of how this is done.

Processing the raw hides: When they first arrive, hides are trimmed and soaked to remove excess tissue, salt and other solids and to help restore moisture to the hide that was lost during curing. Hides are separated and put into batches inside large wooden drums and begin processing by soaking in cold water which then has detergent, salt and other chemicals added. These drums are turned and water is changed out until the water is clean and the skins are now rehydrated. This process is an important step towards creating leather and allows the skins to relax. If done incorrectly you may be left with patchy inconsistent hides unable to be used.

At this stage the clean hides still have animal hair on them. The grain side or the surface of hides which contain the hair and glands is the thicker and softest part of the hide. This must be removed as well as hair in the roots of the hide. It is important to have the follicles in the grain of the leather as clean as possible and to de-hair the hides. This process is done by what is called liming. Liming is the process of hair removal and use a series of pits or drums containing lime liquors (calcium hydroxide) and sharpening agents. This dissolves the hair and no damage is done to the dermis part of the skin due to liming. Advantages of this process are that it will open up the skin of the hides to allow for thorough penetration of the tanning materials in later stages.

Following liming, sometimes the hides have a high alkaline concentration and this must be lowered considerably in order for tanning to begin. This process is called de-liming. If this has happened then a chemical is used often like ammonium chloride. The hide will begin to un-swell which is caused by the neutralizing of the lime. This in effect washes out the skin. Bating is the next step which takes the hard skin of the hide and is done to make the skin softer, smooth and relaxed. Enzymes are used to do this and these particular varieties vary by the specific tannery. Scudding is the final step before tanning begins and the purpose of scudding is to remove any remaining hair-root or surface fats which get squeezed out of the skin. Most often this is done by placing the hide on a round board and a blunt knife or tool is run over the grain of the hide. Few tanneries however still do this by hand and the process itself has become something more handled through human operated machinery.

In this article we examined the beginning stages of how raw hides are processed. We looked at how the hides are cleaned by using large wooden drums with a mix of detergents and chemicals. We went on to learn about liming which is the process of removing hair from the hide. Lastly we examined batting and scudding and how they are used to soften the leather and prepare the leather for tanning. In the next article we’ll take a look the tanning process and the different tans used to make leather.

About the author:
Phil Pendleton is a furniture professional with over 15 years experience. He has been involved in furniture sales, production and distribution. He continues to work with other furniture professionals to help promote new trends in leather furniture.