In Zen the outer robe is not regarded as a garment covering the practitioner but as something closer to the tradition itself, and the tension in that idea is one the tradition noticed on its own.
More than clothing
The kesa is the Japanese form of the Buddhist outer robe, a rectangular panel of pieced cloth worn over one shoulder. Dogen devoted a chapter of the Shobogenzo to it, and practitioners place it on the head before putting it on, reciting a verse. The rakusu, a small bibbed version worn at the chest, is what a lay practitioner receives at the precept ceremony, and it is frequently sewn by the recipient stitch by stitch with a phrase recited on each stitch, so the object is made as much as worn.
Rags and brocade
The origin of the robe is rags: the earliest monastic robes were pieced from discarded cloth as a sign of renunciation. Japanese kesa became extremely elaborate over time, made from donated court silks and brocade, which sits in obvious tension with that origin. Japanese Buddhist writers noticed the contradiction and argued about it themselves, which is worth recording, because the tension between the poverty the robe signifies and the wealth some robes display is internal to the tradition rather than an outside criticism of it.