There are so many different types of leather.
There are many different tanning methods available, such as pigskin, cowhide, and horsehide, such as tannin tanning and chrome tanning.
Today we will introduce some of them!!

What is the difference between skin and leather?

Leather bags are written as "kawa" (leather) and not "kawa" (skin).
Why is that??

"Hide" refers to the skin of an animal, and "leather" is the material made from that skin.
In order to turn "skin" into "leather", a process called "tanning" is carried out.
"Skin" becomes "leather" through the process of "tanning."

What kind of process is tanning?

Tanning is the most important process for turning skin into leather.
The work involves removing unnecessary protein and fat from animal "skin" and processing it to prevent it from rotting.
I've heard that in the past they would beat it with a stick to remove the protein and fat, but nowadays they do it chemically.

There are two main tanning methods: vegetable tanning and chrome tanning.
Now let me introduce the features of each.

Vegetable tanning

The tannins used in tanning are the astringent substances found in plants.
Tannins have the effect of stretching the fibers of the skin.
The tannins are then used to finish the wine, which takes anywhere from a few weeks to a few months.

The "leather" made through tanning is strong and resilient, and the finishing of the edge (the cut surface of the leather) can bring out the texture of leather.
However, since the leather is made through a very time-consuming process, it is relatively expensive.

Drum tanning


Vegetable tanning drum

The tanning process involves placing the hide and tanning material in a drum and then beating in the tannin.
There are several thick sticks inside this drum, which are struck firmly.
This is a tanning method that has become common in recent years.

Tanning with pit tanning

IMG 7618 Pit tank

This method involves putting different concentrations of tanning agent into barrels and tanning the leather by immersing it in the barrels in turn.
It's a very time-consuming process, and it can easily take around a month to complete.
If the concentration of the tanning agent in the pit tank is incorrect, the soaking time and the leather itself will be wasted, making this a very risky tanning method.

It seems that this method is often used for high-quality Italian leather.

What is chrome tanning?

Chrome tanning is a method that uses chromium sulfate and can be completed in just a few days, resulting in leather that is heat-resistant and highly elastic.
The leather is relatively light and changes very little over time (aging).
The edge (cut surface of the leather) cannot be polished.

It can be done in a short amount of time and at a relatively low cost.

Thank you for reading to the end.

The images used this time are from when I participated in the Tatsuno City Leather Festival and Tannery Tour Bus Tour held on November 19th.
I learned a lot.

In fact, when I saw the scene of "skin" being turned into "leather," I felt that it would be disrespectful to life if we didn't take better care of leather.
I also learned how difficult the process is to turn "skin" into "leather."
Looking back at how I had always looked at delivery dates and said things like, "Can't the leather be finished sooner?", I thought, "Isn't that just impossible?"

Having said that, a bag factory exists because of its customers.
I thought that I would have to find a better balance and continue to search for a line that would satisfy both customers and the people who provide the ingredients.

It ended up being a bit sad at the end though. Haha.

Thank you to Shownan Leather and Almighty for allowing me to tour their facilities.