Guiding me through the various facilities operating within a typical Kojima factory was local resident and Japanese denim pioneer, Whoval's Mr Ishii.

As you wear a pair of jeans, the colour gradually fades at the creases formed around the upper thigh area. What follows is description of the processing that emulates this vintage trait.
Bearing in mind every brand and factory differ, first a model for the crease is made.
Below photo shows a mold resembling an unevenly surfaced board.
The mold is put inside the upper thigh to leg section of the jeans and a special grinding process begins during which the denim is rubbed down by the uneven surface of the cast, thinning the fabric and causing creases to appear. This process is called 'shaving'.
Another process of damaging involves shaving and filing the fabric at the hems by hand, giving the jeans a more used appearance.
A special room

A shape appears inside a dim lit room guarded by a large and solemn looking electric screen. For some reason the atmosphere here arouses distant memories of the ominous score to The Terminator as fine grains of sand whip by me in the sand blasting unit of the plant. This is the technique adopted to generate the widespread used effect in parts of the jeans including the thighs and hips. Within the darkness, the workers barricade themselves from the giant thunders and roars of an immense machine. Cameras cannot be taken near as the splashing sand can be fatal to precision instruments. Obviously, I was bombarded by it.

Several large drums are lined up side by side as part of the laundering process, a technique used to produce an antique effect in the jeans and also accentuate the worn out, damaged look. During the washing process, holes are made in the jeans. This is done because the holes are stronger and more angular when the denim is raw, as it is at this point. It is because of such subtle nuances that Japanese denim is so highly regarded. Spinning for one to two hours at a temperature of 90 degrees, it is possible to wash up to 60 pairs of jeans at one time in these enormous drums.

To produce the stonewash effect, the jeans are washed with pumice stone. Inside the drum, the pumice stone grinds the denim giving the hem and creases an uneven appearance; causing the fabric to fade and increasing the overall vintage look. In the course of the process the angular pumice stone is shattered to pieces, decreasing in weight from 50kg at the beginning to finally a mere 30kg. The "face" of the stone has also changed in recent times as materials other than stone have started to be used.
Also during the laundering process, the cloth at the hems, pockets and so forth, is folded and pinned so that once the washing is complete fine hues at the pinned creases emerge.
Then, bleaching -another crucial aspect in the work, is performed in order to generate a fade out effect in the indigo color.
Finally, human eyes decide when to end the drum phase. After being inspected, the jeans are spun once more at 30 second increments, the exact time adjusted according to what the experts deem necessary. Then, each and every time, the colour is finely tuned and tailored. The intuition of craftsmen refined over years of experience is crucial in every step - distinguishing the Kojima factories from anywhere else in Japan or the world.

After this, the jeans are spin-dried in large tumblers or hung out to dry in the sun. Recently, there has been many orders for such sun-dried jeans because drying in the sun is believed to produce a more natural vintage appearance. In connection to this, I was allowed to visit the drainage facility institution and was amazed to see how clear the drainage water was. Although it can be said the cost of disposal is a fortune, the regulations appear extremely rigid.
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