Attus is cloth made from the inner bark of the ohyo elm — boiled, stripped to bast, hand-spun into uneven yarn and woven on a backstrap loom. The result is a mid tan-brown fabric with visible slub, light and water-shedding, and it is the field, not a backdrop.

Onto that ground Ainu women laid bands of indigo-dyed cotton tabby and worked off-white thread over the appliqué edge. The motifs — morew, the spiral, and aiushi, the thorn — are protective, and they obey one rule: every drawn line begins and ends squared off.