Understanding Leather
The History of Leather
The leather industry is one the oldest industries known to mankind. Our earliest ancestors used skins to protect their body, hands and feet. Leather is made from the skin of any animal, reptile, bird or fish through a process known as tanning. This process preserves the skin which would otherwise quickly putrefy or decay.
Today the leather industry is scientifically based. Research is continually carried out to ensure the product is improved using the latest technology to meet modern day needs.
With few exceptions hides and skins are by-products. Animals are reared for meat, milk and wool, not for the value of their skins. As a consequence, the tanner is not able to control the supply of raw hides.
The availability of cattle hides for leather is however fundamentally dependent upon consumer demand for beef. Today worldwide, at least half the leather produced goes into footwear, and around a quarter into clothing. Only around 15% goes into upholstery and the rest into small leather goods and other consumer products.
Because of its durability and comfort, leather has been used for seating purposes throughout the history of transportation and furniture. The early leathers were made from cowhide, calfskin, pigskin, deerskin, and goatskin leathers. The hides and skins coming from animals either hunted or farmed for food purposes. The present trend is for most upholstery to be made from Bovine material (that is to say cattle hides) as this is readily available and best lends itself to the modern demands of designer, producer and consumer. Far from waning in popularity, leather continues to be the material of choice for many people.
The Manufacture of Upholstery Leather
Curing - This is a method of short term preservation, done by sprinkling salt on both sides of the hide.
Soaking - On arrival at the tannery the hides are soaked in water to remove the curing salt.
Liming - The hair and epidermis are removed by treating the hides in a solution of lime. The hide also swells up in this process, which gives the finished leather the required softness and flexibility required for upholstery purposes.
Tanning - This is commonly carried out with the aid of a mineral salt which penetrates the hide very rapidly, tanning being complete in twenty-four hours. The leather is a pale duck-egg blue in colour, and after suitable processing yields fine soft modern leather. A wet drum process allows the addition of dyes, anti-mould chemicals, a re-tan agent, fat liquors to give the finished product a soft feel, and where necessary, flameproof chemicals.
Drying - Hides are dried by first of all wringing excess water out in a large mangle, and then by stretching the hides on a frame which is then passed through a large heating chamber.
Pigmentation and Lacquering - Finished hides will have pigments applied to the surface. A top lacquer coat is applied to give the finish a layer of protection against wear and soiling.
Drumming - The hides are placed in large stainless steel drums and tumbled. During this process the natural fibres start to loosen and a soft feel is created.
The Natural Characteristics of Leather
Real leather is a natural product. It breathes, is warm and has individual characteristics which make each hide unique. Leather will always bear the marks of its natural origin and these characteristics can show as healed scars, growth marks, areas of differing fibre density and hair pore structure. These hallmarks in no way detract from the wearing qualities of the leather. They are signs discerning owners cherish when buying leather. With the passing of time and use, it develops a patina which enhances its beauty.
Growth Marks and Veins - These are an indication of the age of the animal and in that respect are similar to the graining on a piece of timber. They range from often quite pronounced marks in the neck area to subtle bands across the hide perpendicular to the backbone.
Scars - These form usually as a result of barbed wire damage or by the horns of other cattle. In their healed form the new skin is as strong as the remainder of the hide.
Grain Variation - The fibre texture varies greatly from being loose in the belly and flank areas to being relatively tight across the backbone. The looser areas consequently have more stretch.
Shade Variation - No two hides are alike and due to the varying grain structure mentioned above the dyes and finishes penetrate to differing degrees in different parts of the hide to give an attractive variation. Whilst every attempt is made to achieve uniformity this is not always possible.
Craftsmanship
Leather cutting is a highly skilled job and time consuming. Being a natural material, the aim is to keep wastage to a minimum while preserving all the natural character of the hide in the piece being made, whether it is a car seat, headboard or a sofa.
Likewise when sewing leather, extreme care must be taken, as unlike fabric, when leather has been stitched, it cannot be unstitched and re-sewn as the old needle holes will be visible.
Finally when upholstering in leather, great dexterity and strength is always required due to leathers natural characteristics.
