Tossa jute
Jute from Corchorus olitorius, one of the two cultivated jute species, and a fiber that shibari rope makers such as Amatsunawa name on their products.
Tossa jute is the trade name for jute from Corchorus olitorius, as distinct from white jute, which comes from Corchorus capsularis. Sources do not agree on which fiber is better. In the PROSEA fiber-plants handbook, olitorius comes out ahead on fineness, softness and sheen, with a fiber tinted from yellow to red, while capsularis fiber tends to be pale. Wikipedia’s white-jute article, citing an encyclopedia of cultivated plants, instead calls capsularis fiber whiter and of higher quality. Some makers of bondage rope state the species: the Japanese-style rope maker Amatsunawa, for example, describes its yarn as 100% Corchorus olitorius tossa jute and lists the batching oil and processing of each rope separately from the fiber itself.