It is said that such decoration was originally remains of white binding strings knotted in the form of flowers and attached to the ribs, but in the early modern times it was a family crest stitched with white strings on white plain silk (or habutae, a thin, soft, durable silk).
これは元来白い綴じ糸の余りを花などのかたちにして貼ったものともいうが、近世では白平絹（羽二重なども可）に白糸で家紋の形を縫った。