I've always been interested in how things are made. That interest may even be what led me to starting my own business. And as you know, most of our products are created with leather. I thought it would be interesting to learn how the leather is made before it gets to me, or even before it gets to the tannery. I've talked before about Horween Leather and how they tan leather, but how are raw hides created before they get to Horween?
It Starts With An Animal
Leather is a product made from animal skins. It can be made from the skin of almost any animal, which means the first step to creating leather is to decide which animal to make it from. Most leather is made from cows, buffalo, pig, sheep, and lamb. Occasionally, you'll also see leather from deer, alligators, sharks, crocodiles, and even stingrays.
The type of animal leather comes from shapes the quality of the leather, the color and pattern of the leather, and the price of the hide. For example, leather made from crocodile skin is very tough and sturdy, while leather made from sheep skin is soft and smooth. Stingray and shark skin leather are hard to come by and can be some of the most expensive leather.
Preparing the Skin
Once the animal is selected, it has to be skinned. This is a delicate process. If not done correctly, you can create holes in the skin early on which limits the size and usability of the hide. Depending on the size of the animal, the techniques and equipment needed to properly skin it can change, but in general the idea is to keep the entire hide in tact but able to be laid flat.
Once the animal has been skinned, it then needs to be scraped. The goal is for the hide to be the same thickness everywhere and for there to be no folds in the skin. Once it is skinned and scraped, it needs to be lain flat. Often it is stretched out on a board so it can be as flat as possible.
Curing the Skin
The hide needs to be stretched out and cured in some way to keep it from deteriorating over time. The most common way to cure leather is with salt. Salt is poured over every bit of surface until it looks completely white. The salt saps the moisture from the skin, and the ultimate goal is to dry the skin out. This process has to be repeated every few days.
Although drying it with salt will keep it from rotting for up to a couple of weeks, eventually the skin needs to be saturated again to complete the curing process. It is soaked in a chemical mixture that includes water and alcohol. This process is similar to the process of making a pickle! Typically if the leather is going to a tannery after the fur is left on at this point, although if the goal is to make raw hides this would be the time to pull out the scraper and scrape any fur off the skin. The water softens to pores and makes it easier to accomplish during this step.
Drying the Skin
Once the hide has been cured, it needs to be dried out. It can either be stretched and air dried or it can be smoked. Either way the result is a cured rawhide that will not rot over time. In fact, rawhides used to be used for a multitude of purposes, including to make structures and even casts. Today, rawhides are still used to make whips, lampshades, and even dog treats.
The rawhide is also what gets sold to a tannery to be tanned. Tanneries can spend a lot of time investigating rawhides and selecting the exact right color and pattern for their needs.
Tanning the Skin
Rawhides are shipped to tanneries, which all have a slightly different process of tanning the hide into leather. At the most basic level, however, the steps are the same. The first step is liming. This is where any remaining fur and fat is scraped off, as well as some of the natural grease on the hide.
The next step is deliming and bating. This softens the skin and lowers the pH. The pH is further lowered through pickling the skin. Once the skin is soft and supple, it is ready to be tanned. Different companies tan using different chemical compounds. Horween Leather does combination tanning, which means they start with chrome tanning and then follow up with a vegetable retanning so that they have the benefits of both major tanning processes while limiting the drawbacks.