Necklace Tubes and Tube Bails are the most popular bails for rattail.
Rattail cord (both our original rayon variety and the newer nylon) is excellent for Kumihimo. The smooth, shiny texture braids well and looks great. Just try to avoid soaking it, because the color may run when wet. (Hey, we wear-tested the new nylon style and we're excited to say that its color stays where it belongs!)