From the early ages when the prehistoric man first started using it to shield his body from the severe elements of weather during the glacial epoch to the modern times – leather certainly has come a long way. Of course, there are many a good reasons for this everlasting bond between the human and the animal hide. Leather is easy on eyes, it feels and makes us comfortable, and it lasts for generations to use.
In the early days when our forefathers started making use of leather, it was merely the remnant skin of the hounded and killed animals, which they essentially hunted to feed themselves. Having cleaned this raw skin out, they would simply start wearing it in whatever way it felt comfortable to wear. They would also wrap their feet it and use it as footwear to safeguard themselves from brutalities of rugged terrain. This would work fine and provide the desired protection to the body, however, after some time the leather, being an organic material, would soon start decaying and putrefying rendering itself not only useless but also unbearable to stand. Sadly, they neither had the knowledge nor the experience to figure out the ways to prevent these hides from decomposing and preserve them.
As time went on, they started experimenting with the ideas of preservation and realized that there were several things they could use that would slow down the putrefaction of the hide. For starters, they realized if they straighten the skin, stretched it out, and let it dry in the sun, the skin becomes hardened and firm making it to last much longer. Gradually, they found out that if they rubbed a variety of oils or oily matters into the skins, it softened the skins and made them supple. Fast forward a few centuries and possibly millennia, it dawned upon the man that the bark from certain trees contained a compound called “tannin” aka tannic acid, which could be useful in converting raw skins into leather, as we know of it today.
In traditional and puritanical terms, Napa or Napa Leather or Nappa was referred to the only sheepskin for its suppleness. However, over the years the term Napa has come to represent any type genuine leather that is soft and supple in touch and feel. So, now there is Cow Napa along with Lamb Napa that is widely in use today. Due to its suppleness, it is primarily used in leather apparel, furniture upholstery, and handbags. Napa leather has following sub categories –
Pure Aniline Leather: This leather is tanned and dyed with water soluble transparent aniline dyes with no direct surface treatment or any finishing coat application.
Full Aniline Leather: This leather is tanned and dyed with water soluble aniline dyes and coated with a transparent seal coat.
Semi-Aniline /Aniline Pus Leather: An aniline dyed leather that is finished with a clear top coat, color base, and a top coat.
Spray-Finished/Pigmented Leather: This leather is sprayed with a transparent seal coat, base colored and top coated for a uniform finish. Needs to be buffed and embossed for finishing.
Nubuck leather is essentially aniline leather, the surface of which has been sanded or brushed and polished for it to have a velvet like nap of protein fibers creating a texture with lush and luxurious appearance. So, if you were to run your hands over this textured surface, it will show the difference in shading as you go along, just like in velvet. Nubuck leather is often mistaken for Suede or reversed leather, which it is not. The basic difference between the Nubuck and Suede is that Nubuck is the outer grain side of the hide buffed and the Suede in the inner side buffed to a smooth finish.
The Suede is generally made by buffing and sanding the inner side of the skin or hide to create a smooth finish. Suede also could be made by splitting a thick hide.
Split Grain Leather is the leather that is split from the lower side of the hide after the top layer has been split off for the purpose of creating higher selection leather. While the leather goods made from this layer are still acceptable, they are considered inferior in quality as compared to the products made from the top layer. This is because the split leather portion of the hide does not have as strong fiber structure as the top layer does. The leather will also not show the natural marking that a top layer would show. This leather is used in producing goods when affordability is important.
Corrected Grain or Top Grain Leather is probably the most misunderstood term in parlance of leather goods. People often confuse Top Grain Leather, which is a less expensive type of leather with Full Grain Leather, which is the top quality leather and therefore expensive. Top Grain Leather typically is defective leather that has been artificially stamped to look like natural grain and is usually heavily pigmented.
Pull-Up Leather is a full natural grain leather that is aniline dyed and finished with oil or wax to give it very soft hand or feel and other unique characteristics. If you stretch this leather the oil and color in the leather temporarily shifts making the pulled areas lighter in color. Ergo, the name Pull-Up Leather. Due to its honest nature and unique characteristics, this leather is very popular where aesthetics are important.
Patent Leather is more or also the same quality leather as any with a high-gloss lacquer coat applied to it in its finishing stages to give it a shiny and reflective surface. Used primarily in making of shoes, apparel, belts, and purses.
Bonded leather doesn’t come from whole hide of an animal but is reconstituted by shredding, grounding, and pulverizing the leather scrap and leather fiber and then mixed with bonding materials or glue to recreate the leather sheet. Primarily used in inexpensive furniture and book binding etc.
Tanning is the process where a raw animal hide is processed with a series of treatments to transform it into ready-to-use leather for a variety of purposes. The tanning process essentially changes the protein structure of the raw animal skin permanently and turns it into a robust, usable, and everlasting material that will not deteriorate and fester. There are primarily two methods of tanning that are widely used today i.e. Vegetable and Mineral.
This is the traditional method of tanning a hide that was carried out by using the “tannin”, a compound derived from oak or fir trees among others. This is where the word Tanning comes from. In this process, unhaired, desalted, and defatted animal skins are soaked in large tubs like containers called “vats” filled with tree bark. The skin absorbs the tannins from the bark and helps it transform it into leather of certain unique characteristics while preserving it from further decomposition. What happens at microscopic level is that the tannins from the bark form a bond with collagen proteins in the skin and completely cover them to essentially make them less water soluble. This helps make the hide resistant to bacteria and other saprophytic organisms preserving its durability and characteristics. This process is painstaking and time consuming often taking weeks to come to fruition. This is the reason fully vegetable tanned leather is much more expensive than the chemically treated ones.
During the Industrial Revolution, the tanners felt a need to come up with an alternate tanning agent that is effective, efficient, and that considerably shortens the time it takes to tan the hides using traditional vegetable tanning methods. They started using Chromium Sulphate solution to tan hides. This is known as Chrome Tanning and is one the most widely used tanning methods in the world today. In the pre-tanning process, the hides are “pickled” for acidic conditioning by repeatedly treating them with acids and salts. Once the trivalent chromium penetrates the hide forming a complex, the pH level of the hide is raised in a process called Basification. This process allows the chromium complex to firmly adhere and bound to the collagen protein of the hide forming cross-links. The basification process continues until chromium protein complexes turn into stable structures. The leather that comes out of the Chrome tanning process has light blue color in this its semi-finished stage and therefore call Wet Blue. A lot of leather is sold and shipped in this semi-finished stage to tanneries around the world who process the leather further to bring it the finished leather stage.
The outcome from these two tanning methods is quite distinctive leather in terms of look and feel and both of them used for different purposes. While Vegetable Tanned leather traditionally has been used in more “heavy leathers” such as shoes, belts, travel bags, and saddles, etc., the Chrome Tanned leather being more supple and stretchable is preferred in producing apparel and small leather goods.
Leather is a very resilient material and quite capable of handling the inflictions of time on its own without much effort on your part. However, taking a little care here and there will go a long way and truly make your leather products last forever…well, almost.
For starters, moisture is certainly one of the most potent enemies of leather and therefore must be kept at bay to shield your leather products from its humid menace. So, we recommend to always store your leather products in dry and moisture free place. Leather is not too fond of direct heat and sunlight either and would rather like to be stored in a cooler (but not humid) place. Also, applying a little wax or leather conditioner occasionally will nourish its appearance and help it look its best for years to come.
Body oils, dirt and perspiration in high wear areas can migrate through the top coat and cause the treatment coats underneath to separate from the leather surface. The proper care and attention to leather can increase its life. Tips to increase the longevity of your leather are as follows:
Keep the leather pores free from dust particles. Wipe the leather weekly or monthly depending on how often it is used. Use a cloth dampened with distilled or purified water to avoid leaving lime scale residue, and dry with a soft cloth. (Not recommended for Nubuck leather)
Don’t place leather near a source of heat or in direct sunlight. It may dry out or fade over time.
Don’t use saddle soaps, oils, abrasive cleaners, soaps, furniture polish, varnish, solvents and silicones or ammonia water on your leather. These vary widely in strength and in compatibility with leather finishes, and may cause cracking or other damage to the leather surface.
Never put adhesive stickers like name tags on leather or suede clothing as glue will permanently mark its surface.
Avoid spraying hairspray or perfumes while wearing leather garment and never apply pins or adhesive materials to the garment as this will damage the hide’s finish.