There are broadly two types of sewing threads and threads used in Head Factory products.
There are many more variations when you include the color and thickness of the thread, but there are two types of thread itself.
The first type that is mainly used is polyester sewing thread.
In the past, when synthetic sewing threads were not yet in circulation, threads made from natural materials such as linen and cotton were the mainstream.
Of course, even today, natural yarns are still used in a variety of situations, with textures that cannot be achieved with synthetic fibers.
However, when compared in terms of strength, polyester and nylon synthetic yarns win.
Furthermore, if you are concerned about strength, there are threads made from Kevlar or Zylon, which are used in bulletproof vests, etc., but if you choose a material that balances the strength with leather, polyester thread is the best material.
The other type is sewing thread called "koa".
This is a rather interesting thread; at first glance it looks like cotton thread, but it has a structure in which a thin polyester thread runs through the center of the cotton.
It is an excellent product that combines the texture of cotton thread and the strength of polyester thread, and Head Factory uses this thread depending on the design of the jacket and the type of leather.
However, when I prioritize strength, color development, and the gloss of the thread, I choose 100% polyester, and this is still my main choice.
The other day, while having drinks at a red lantern with a friend who does leather crafting for a living, we started talking about thread.
He uses waxed cotton thread or sometimes artificial sinew thread, but when the topic of strength came to mind, he suddenly exclaimed, ``If strength is your priority, then you should use spider silk!''
I knew spider silk was strong, but he said, ``It's stronger than Kevlar.''
I had been drinking that day, so I played it off as a joke, but when I remembered it later and looked it up, I discovered something interesting.
It has been scientifically proven that spider silk is several times stronger than Kevlar when comparing the same thickness, and the silk produced by a then new species called Darwin's bark spider discovered about 10 years ago is It is extremely tough, and its strength is said to be 10 times stronger than Kevlar thread.
If a huge net were made of spider silk tied together to the thickness of a pencil lead, it would be strong enough to catch a crashing plane.
What was even more surprising was that artificial spider silk had already been developed, and the fiber, named ``Kumonos,'' was apparently beginning to be used in some manufacturing fields.
Although it is not yet available as sewing thread, it may be possible in the near future that we will be able to make leather jackets from spider silk, even though it is synthetic.
No, probably not, because the main character is the leather, and it shouldn't be strong enough to damage the leather.