Stonewashing is a finishing technique in which finished jeans are tumbled in large industrial drums together with pumice stones or another abrasive material, sometimes alongside enzymes that achieve a similar effect with less physical stone. The mechanical abrasion wears down the surface of the indigo dye, softening the fabric and lightening its colour unevenly, which creates a broken in look.
The result is denim that feels noticeably softer and more flexible straight out of the packaging than rigid or raw denim, with a lighter, slightly mottled blue that mimics years of wear. Because the process is mechanical, the degree of fading can be controlled fairly precisely, giving a consistent, repeatable wash across a production run, unlike the more individual fading that develops from actually wearing raw denim over time.
Stonewashed jeans are a common, accessible middle ground for people who prefer the look of worn in denim without waiting for it to develop naturally. See wash for how stonewashing fits among other finishing methods, and our guide to jeans washes and finishes for more detail.
