Report February 2026

To understand why and how we made KI grade yarn, perspective is relevant to historical context. A period of enlightenment a century ago combined accessible cheap publishing and increasing liberalism when what we now consider kink came out of the shadows. First by written word, then breaking barriers with illustrations. Following the authoritarian nationalism which quelled niche enthusiasm, post–WWII, especially in Japan, photography, and later video expanded interest.

Demand for bondage rope was insignificant. Evidenced in reader submitted images in Kitan Club to the mid-1970s, pretty much anything flexible and knotable can be seen. Eikichi Osada exclusively used cotton. Toshiyuki Suma and Chimuo Nureki, then Kenji Matsui and Akechi Denki turned from waning stocks of pre–ban Japanese hemp to Bengali jute due to its excellent characteristics for Shibari, and most Japanese Kinbakushi followed suit.

The internet had a huge effect, initially accelerating interest in kink as information became borderless, making national regulations ineffective. The 50 Shades phenomena catalystized millions, realising the normality of adult fantasies. A swing from consumers to practitioners took place within a decade. Spectators were no longer satisfied surfing speciality websites, but sought to actively participate firsthand.

Remarkable growth has followed. But rope is made for completely different applications. Everyone is entitled to chose and procure as they wish. I wanted the best. As this meant volume, I had to make it available to the community. Getting deeper into the material, the industry, the process and the tech, it became obvious how available yarn grades didn’t suit requirements for longitudinal strength and softness in a Shibari Asanawa rope.

Differing from jute stock market classifications, raw fibre quality is selected at mill sorting graded in 7 steps: ODI, D1/2/3, E1, SMR and Cutting. There are 3 basic yarn grades: Hessian, Sacking and Carpet Backing.

Hessian is a generic yarn for applications where Sacking yarns are too coarse. It’s used to make cloth, shopping bags, finer sacks, agricultural bindings (strings, twines and ropes) and handicrafts. Using D2/3 material, medium count yarns must be spun looser to be flexible enough for fairly tight weaving. Sacking is heavier duty yarn using cheap E1 and SMR material, commonly multiple-plied to avoid sack burst breakage. Carpet Backing, eg. CRM, CRT, CRX, etc. uses D1/2, and is designed for loose weaving, and may be used to make cordage producing less hair and fibre loss than Hessian.

All 3 grades are commonly Tossa sometimes blended with cheap Meshta for cost efficiencies. Waste hackled from fibre used for Hessian and Carpet Backing is reused in E1 and SMR, with Cutting unusable for yarn. There are speciality yarns, eg. fine White used for cloth, cotton–jute blends, etc. We wanted to make a yarn engineered exactly for Shibari, impossible without completion of our self-built state-of-the-art yarn mill.

We experimented with raw material, blending rare ODI with D1. Unfortunately, ODI is far more expensive, hackling removes 30~40% bulk material, and seasonal differences limit availability. In requiring a consistent, repeatable product we opted for 100% D1 Tossa. We needed to understand and reduce hairiness and fibre loss. There are 2 hairs to each fibre – the ends. The more broken the fibres, the more hairs. The smaller the fibres, the more fibre loss. It’s that simple. Analysis on the machinery, observing, measuring, asking questions led to components modified, speeds lowered and soybean oil batching blend adjusted, etc. until we found the optimum settings. These were made into rope at each iteration and tested in real conditions.

The specification for KI (KOUMANAWA Ito) overcame issues with soybean oil batched yarn in stranding and rope–making. The improvement to longitudinal strength permitted the increased softness to pass through tooling at 10% looser lay without generating compression waves for a stable end product. And finally, we found the sweet spot of how to manufacture jute Shibari Asanawa rope for our needs – SHIZEN. We hope you enjoy working with it.

Note all rope manufacturers identify production spools with a label (Jp. Mamefuda). If you don’t find one, you should be cautious of the source. Beware of untrue, misleading, or deceptive statements to promote products or services claiming, eg. Hand made in Japan without evidence. KI and SHIZEN are machine made by experts at Japanese owned and managed sites in Bangladesh.