Roll up a sweater sleeve. The wrinkles are not random. They're either accordion folds propagating sequentially from the compressed end, or helical ridges that appear simultaneously across the entire surface. Which pattern you get depends on the ratio of circumferential to axial stitches — the geometry of the knitting, not the material of the yarn.
Tanaka et al. compressed knitted fabrics wrapped around rigid cylinders and systematically varied the stitch counts. The transition between accordion and helical modes is sharp. But the helical wrinkles carry an additional signature: their chirality — which direction the helix spirals — is determined by “subtle structural asymmetries introduced during manufacturing processes, including the tension applied during knitting and the direction of sample assembly.”
The asymmetry is microscopic. A slight difference in loop shape caused by the tension of the knitting machine. The direction the fabric was sewn into a cylinder. These are not properties of the fabric's design. They're artifacts of its manufacture — the particular hands, the particular machine, the particular moment of assembly. And they determine the macroscopic buckling mode visible to the naked eye.
The wrinkle pattern is a fossil record of how the fabric was made. The accordion mode tells you the geometry. The helical mode tells you the manufacturing history. Not the intended design, but the actual process — the asymmetries that were never specified, never controlled, and never intended to matter. They matter because buckling amplifies what equilibrium suppresses. Under compression, the smallest structural bias becomes the organizing principle.
This inverts the standard engineering assumption about manufacturing tolerances. Tolerances are usually understood as noise to be minimized — deviations from ideal that degrade performance. Here the deviations don't degrade the wrinkle pattern; they determine it. The tolerance is the signal. What the manufacturer didn't control is exactly what the failure mode reveals.