The plastic of the ancient world, ancients put it to myriad uses
By Brannen Basham
A defining characteristic of impactful inventions is longevity. Although human ingenuity has led to countless technologies, relatively few have persisted for long. While future generations will most likely miss out on the wonders of another Tamagotchi revolution, their shoes, belts and jackets will almost certainly be very similar to our own due to one of the most impactful human inventions yet created – leather.
Early humans quickly realized that the skins of their prey could be tanned and used as protection from the elements and predators. It isn’t prudent to give humans all the credit for leather’s usefulness, however. Although we eventually stumbled on a way to create leather from raw animal hides, the real reason behind leather’s effectiveness comes from the skin that it starts as.
Our skin usually doesn’t get enough credit. While insects and similar invertebrates rely on tough, rigid suits of armor for protection against the wilds, vertebrates have developed multiple layers of tissue on the outside of their bodies to protect themselves from disease, prevent rapid water loss and to help better interact with the world around them. Human skin, for example, has up to seven layers, each with a specific function.
The skin of each animal is different depending on the needs for survival. Stingrays pack their skin with calcium in order to avoid sand rash, while octopuses and chameleons are able to open and close special cells in their skin in order to change color and appearance. Even though our multiple layers of skin work wonders at warding off microscopic pathogens, studies have found that our bodies enlist the help of beneficial bacteria in the fight against invaders as well.
These bacterial bouncers end up living on our skin and add an extra layer of protection. Underneath the outermost layers of skin, networks of fibers help to retain elasticity. Our skin is constantly shedding off layers and renewing them, and the average person drops about a pound of skin cells a year. This helps to repair any damage while also shedding any unwanted hitchhikers. Leather, with its innate weather and rot resistance, clearly beats our skin in terms of brute resilience.
Early humans learned that by covering animal hides in fats and smoking them, these skins would become tougher and more resilient. Slowly, and most likely by accident, early clothiers discovered that by mixing animal hides with tannins from plants and other ingredients, they could transform raw animal skins into tougher materials that better resisted the elements and were generally immune to decomposition.
Leather was the plastic of the ancient world, and it was used for almost everything. There are even stories of bustling cities relying on leather pipes for their sewage and water systems. Leather’s resilience comes from the tanning process, wherein chemicals react with the protein fibers in a hide, bringing them closer together and bonding them to each other. This ultimately creates a tougher and more rigid material.
For thousands of years leather was made by utilizing specific chemicals found in certain plants. Recipes differed between families, but oak was commonly used as a main ingredient in tanning mixtures. Only about 10 percent of leather today is made through this method, and instead modern tanneries utilize compounds such as sodium dichromate, which can accomplish the same process in a fraction of the time.
While modern tanning technologies are generally faster, more precise and far more damaging to the environment, the final product is remarkably similar to leathers used hundreds and even thousands of years ago. However, in the grand scheme of things, simple resilience is no match for the flexibility, protection and amazing regenerative qualities that our skin provides on a constant basis.
Brannen Basham and his wife, Jill Jacobs, operate Spriggly’s Beescaping, a business dedicated to the preservation of pollinators. He can be reached at email@example.com.