Here's an article I just sent to EJMAS.
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Mats for Cutting
By Guy Power
I used to get the tatami-omote I use for test-cutting through a friend in Japan. The tatami-omote were good and inexpensive (free); however, they were used and the tatamiya-san was happy for my friend to come around to collect his garbage! But they arrived dirty, and musty, smelly, moldy, and always took my breath away when I opened the package. Once I even found "dani" (mites) crawling around --- Eewwwwww!
Then my friend went to England, leaving me madly looking for inexpensive material to cut. I ended up buying beach mats from wherever I could find them. Then I discovered Mugen Dachi, which sells brand new, unused, fresh, clean, green tatami-omote. So new in fact, that the ends have not been trimmed to fit the tatami; the ends are little "bushy" when rolled up and you may require an extra 1/4" (6 mm) of spike to firmly seat their makiwara.
So on July 22, 2000 I conducted a test to compare commercially available beach mats and Mugen Dachi (www.tameshigiri.com) tatami coverings. This report is the findings of my test.
Mugen Dachi Tatami-omote
The Mugen Dachi mats are made of new double-ply construction. They are purpose-made by a Japanese company for the tatami trade and are used as the top cover on Japanese tatami floor mats. These tatami-omote - as they are called in Japanese - measure approximately 6' x 3' (70" x 35", 178 cm x 89 cm) and are 4" (10 cm) in diameter when rolled and fully soaked. After draining, they are heavy and stiff. Throughout this report I will refer to Mugen Dachi's product as "tatami-omote."
Cost: $3.50 each (lower prices are available for larger quantities).
Retailer: Mugen Dachi
Beach Mats
These Chinese-made mats are sold as beach mats and have thin colored cloth borders with two tie-down straps sewn along the perimeter of the short sides. These beach mats are of a flat single-ply construction and are very thin compared to the robustness of the fibers used in the Mugen Dachi tatami-omote. One mat rolled up measures about 1.5" (3.8 cm) in diameter when soaked for eight hours, and is very flexible. Three mats rolled together measure about 4.25" (10.8 cm) after soaking; however, they are still flexible and pliable compared to tatami-omote. Throughout this report I will refer to this product as a "beach mat."
Cost: About $1.25 each.
Retailer: Various shops in San Francisco's Chinatown; Pier 1 Imports; etc.
Test Preparation
I prepared both products identically one day prior to the test. After folding the mats in thirds and tightly rolling them, I affixed each makiwara with five rubber bands. To obtain like-sized targets, I had to use three beach mats per makiwara; however, I needed to use only one piece of the Mugen Dachi tatami-omote per makiwara. Both brands of makiwara were mixed together and simultaneously soaked for a period of 10-12 hours. After six hours elapsed, I rotated the mat mixture to ensure each makiwara had equal time in water. (Makiwara float, even when waterlogged, and especially when piled upon each other in a stack; rotation alleviates the problem of the top makiwara being semi-moist or dry.)
Three hours prior to the test I removed all makiwara and stood each one vertically, allowing excess water to drain. When the test session began, both brands of makiwara were heavier and "meatier" than in the dry state. However, the beach mats were noticeably lighter in weight and more flexible compared to the tatami-omote.
Tameshigiri
I prepared five makiwara of each type and used a vertical-post tameshigiri stand with a 5" (120 cm) wooden spike to transfix the makiwara. The cuts were executed using a Nosyuiaido "steel iaito." Air temperature was 82 degrees Fahrenheit (28 degrees Celsius); winds were easterly at 5 knots (just joking - I was inside the dojo). I executed between four to six cuts on each makiwara, using left and right kesagiri (downward diagonal cut), gyaku kesagiri (upward diagonal cut), and suihei giri (horizontal cut).
The three-piece beach mat makiwara provides a soft target and I found that I needed less strength and blade velocity to cut through the beach mat makiwara. The mats are very forgiving if you slap-strike them with your blade, but the makiwara bend slightly at the base during the cut, especially with suihei giri.
The single-mat Mugen Dachi makiwara are heavy, stiff, and "meaty," definitely requiring proper blade angle-of-attack, velocity, and strength. When you hit this target, you get the substantial feel and sound ("ssssszzzip") that are lacking in the beach mats. The tatami-omote are green and also have that "smell of Japan." I did not experience makiwara-bend as I had with the beach mats; these were nice and firm. If I didn't cut suihei giri well, I obtained a solid "thwack" with a resultant scoop in the makiwara. It did not bend at the base.
Cutting a two-mat Mugen Dachi makiwara is a real test of one's skill. Although I often cut two-mat targets, I did not include those metrics because a two-mat makiwara becomes a test of the sword and the swordsman rather than the target material. However, it was fun - the gyaku-kesagiri was especially challenging.
Analysis
The beach mats are good for beginners, but the Mugen Dachi mats are better for experienced practitioners and can be cut in half for use by beginners. Therefore they are my recommendation for cutting. And, while initially the Chinese beach mats seemed cheaper than Mugen Dachi's tatami-omote, cost per makiwara is essentially the same:
Mugen Dachi tatami-omote --
$3.50 each
1 mat per roll = $3.50 per makiwara
Beach mats --
$1.25 each
3 mats per roll = $3.75 per makiwara
Therefore I recommend Mugen Dachi tatami-omote for cutting.
Availability
David Wilson of Mugen Dachi says the company always has tatami-omote available and that you can buy any quantity, no minimum. However, you can combine orders with other people to get a price break if you would like. Price breaks currently occur at 320 pieces and 620 pieces per order.
Point of Contact: David Wilson
e-mail: mugendachi@tameshigiri.com
URL: http://www.tameshigiri.com