In the summer of 2019 I visited the Daruma Yokota thread dyeing factory in Kyoto, Japan. As our wholesale company, Orimono Imports, is a distributor for the brand and our retail shop, Kimonomomo has sold their thread for several years, I was hoping to learn more about the dyeing process and brainstorm some new ideas. In both regards, the visit was a resounding success.

Kyoto is typically hot and humid in summer, so much so that I always get blisters on my feet, no matter what kind of shoes or sandals I wear. With all the walking I do it seems to be inevitable. However, I was told that inside the factory it can get up to 45C / 113F and once was so humid the humidity gauge broke. It’s hardly surprising when half the space is filled with industrial steamers and washers.

The sashiko thread starts off as plain raw cotton thread, heaped in large skeins. The skeins are washed and stretched to achieve uniform density and strength.

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After steaming and stretching, it’s time for a wash. Or two. Or… more.

250 kilos of thread and 3,000 liters of water are heated to high temperatures for several hours to remove dirt and impurities. Once the thread is clean, it goes through a second bath, this time with bleach. The process is repeated multiple times to remove the bleach and achieve a bright white color.

The thread is mercerized and prepared for dyeing.

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Here you can see how the dye is applied to the thread. The actual dye formula for each color is secret–it’s the one part of the factory they said I couldn’t photograph. The dye master takes great pride that each dye lot is the same, batch after batch, year after year.

Note how the dye formula is added at the far left. It emerges from small holes in the metal rods holding the skeins and flows through the fibers. As you see the dye master patting the threads in place, be aware that the water was quite hot!

The thread takes a hour to dry, setting the color and sizing the thread to ideal specifications.

The result? Colorfast sashiko thread with the same color and weight, every time.

Want to dye your own sashiko thread? You can! We now have Prepared For Dye thread available here.

You can see more from the factory here, on the Daruma Company site. We are very grateful for their assistance and generous time to help our company learn more about the products we can offer our customers.