While it’s no secret where leather comes from, what’s less understood is the actual process that takes a rough animal hide and transforms it into the lush, soft and colorful covering that adorns every piece of Currier’s real leather furniture. Making leather is a lengthy and technical process that requires precision and care in order to produce a high-quality furniture covering with the same finish each time.
At its core, real leather comes from an animal hide. Leather can be made from the hide of almost any animal including pigs, sheep, goats and crocodiles. However, the most common hide used is that from a cow. A by-product of the meat and dairy industries, the art of making leather uses hides that would otherwise be destroyed. Rather, by making leather, the animal’s hide is turned into a beautiful and useful material that will last for decades.
Of course, the upbringing of the cow will affect the quality of the hide, with a good hide giving an 80-90% yield. On the other hand, cows that have been branded, been exposed to a lot of insect bites or harsh weather, kept near barbed wire or have had electric cattle prods used on them can have damage to their hide. In these cases, hide yield is more likely to be around 60% in order to minimize blemishes and holes. Hide yield also can be impacted by an animal’s diet. Animals that are fed a lot of grains or growth hormones can result in a poorer quality hide.
Once the hide is removed and cleaned, it is salted generously or placed in a salt brine. If a hide is not salted, brined or frozen within a few hours, it can start to deteriorate and become useless. The hides remain salted until they are ready to be processed, whereby it is soaked in water to remove any dirt and residue.
Any hair on the hide is removed with a chemical solution containing calcium oxide (also called a “lime bath”). This soaking process can take up to two days and will help to soften the hide. Hair also can be removed by hand (in lieu of chemicals), but this process is much more labor intensive.
After all this bathing and soaking, the hide is full of moisture. It will swell to around 4mm thick, enabling it to be spliced into two layers. This is done so separate parts of the hide can be used for different types of leather products. The upper part of the leather is saved for the highest quality leather products such as full grain leather. This is because the upper layer has a much tighter fiber structure, making it more durable. In addition, when treated correctly, this layer makes for a stunning and supple leather. This is the type of leather you’ll find in all of the furniture Currier’s sells.
The bottom layer of the hide is used for cheaper leathers with less overall quality. This tends to be used for top grain and split leathers commonly found in shoes, bags and lower-quality furniture.
Once the hide has been prepared, the second stage in the leather-making process is called tanning. This converts the raw hide into leather through preserving the material and halting deterioration.
To begin the leather tanning process, the hide is loaded into a tanning drum along with a special tanning solution. This drum contains a special mix of either vegetable-tanning agents or a chromium salt mix. In general, a vegetable tanning mix, which contains tanning extracts naturally found in tree barks, will produce a leather that is flexible like those found in furniture and luggage. Chromium salts produce a more stretchable leather so it will be used typically in products like clothing or handbags. Tannage also can be combined with both vegetable and chromium salts – this will result in a fuller bodied leather that is both soft and supple. At the end of this process, special fats are added to the leather, which helps it become both stronger and softer in what’s called a liquoring process.
From here, the excess moisture needs to be removed – usually by passing the leather through rollers that squeezes out the moisture. After this drying process, the hides are inspected and arranged in levels of quality, with those containing imperfection being considered of lesser quality. The hide is given a grade, which can determine what it will be used for in the future.
The hide then is shaved to a specified width, with the shavings typically used to make bonded leather.
A second tanning process may occur in order to get the leather fully ready for its intended purpose. This will be a repeat of using either the vegetable mix or the chromium salts (or a combination), with the excess moisture once again removed using pressure.
Once the tanning process is complete, the hide needs to be dried. Drying can occur with a variety of processes including air-drying or vacuum drying. Air-drying involves putting a hide on something like an overhead conveyor where it is rotated until completely dried. Vacuum drying is a quick method of drying, obtained by removing all the air from around the hide. This method will cause the hide to shrink slightly, but will leave the hide with a smooth and tight texture.
During re-tanning, a bleaching agent also can be used to provide a strong base for the dyeing stage.
The leather dyeing process is what adds the wonderful color to a finished leather design. This can be anything from the browns and blacks associated with leather to bright, bold colors. Today’s dyes typically are formulated using highly accurate computers, which enables consistent coloration between multiple batches of leather.
The actual dyeing process can be incredibly lengthy, with hides being added to a large drum along with the selected dye for a long period of time. This ensures the dye fully absorbs into the leather. After around 8 hours, a cutting is taken to ensure that the dye has completely saturated the hide. Failure for the dye to absorb properly will result in leather that looks patchy and inconsistent. Once dyed, the leather is rinsed thoroughly and dried.
Once dyeing is complete and the leather is dry, the last stage is finishing. This is the stage where the leather is worked to ensure that it has a supple, flexible nature and the desired finish. A finish not only protects the leather surface but also makes it easier to clean. This stage is skipped if “naked” leather is desired.
To soften the leather, a machine called a staker is used, whereby the leather is stretched while natural oils are added to lubricate the fabric. The stretching motion also tightens the pore structure of the leather, which helps create a higher quality finish.
The final touch is to apply a finishing spray. The exact finishing spray depends on the desired finish of the leather. However, full grain leathers often skip this stage, as it’s not needed. Instead, this type of leather goes through an ironing process that uses varying degrees of pressure and heat to achieve the desired sheen.
The last stage is a quality check to ensure that the leather has the correct color and is free from tears or other anomalies. Once the leather passes inspection, it is rolled, shipped and ready to be used in the beautiful real Leather furniture you see throughout the Currier’s Leather showroom.