Hello! Today, I’d like to explain the different grades of Igusa rush grass used for the surface of Tatami mats.
Igusa is the name of the plant. By weaving these fibers together, we create the "Tatami-omote" (the woven cover) that defines the look and feel of a Tatami mat.
Most high-quality Igusa is produced in Kumamoto Prefecture, Japan, though it is also grown in China. While the price difference between premium and budget options can exceed 10,000 yen, one of the primary differences lies in the physical structure of the fibers.
Take a look at the image on the right, which shows a magnified view of the fibers.
The round fiber at the top represents high-quality Igusa, while the collapsed, oval fiber at the bottom is used for budget versions. You can also see that the top fiber is densely packed, whereas the bottom one is hollow and sparse. The rounder, denser fibers are much stronger and offer superior durability.
This image illustrates how the color changes over time. The samples are arranged with the highest grade at the top and lower grades toward the bottom.
The right side shows the color after several years. While lower-grade mats turn a reddish-brown, premium mats maintain a more beautiful, consistent tone with minimal aging.
Let me show you a real example. This is a mat I have kept for one year, made with premium-grade Igusa. The left photo was taken when it was brand new, and the right photo shows it one year later.
Brand New
After 1 Year
As you can see, there is very little color change even after a full year.
There is also a difference between Japanese and Chinese Igusa. Chinese Igusa can sometimes have a slightly sour scent that some people find unappealing. Since I can’t convey the smell through an image, I always recommend Japanese-grown Igusa unless a customer specifically requests otherwise.
While the "Premium" grade comes with a premium price tag, most of our customers are very satisfied with "Mid-tier" grades or higher. Quality truly makes a difference in your daily life.