Stone washing is a textile manufacturing process used to give a newly manufactured cloth garment a worn-out appearance. Stone-washing also helps to increase the softness and flexibility of otherwise stiff and rigid fabrics such as canvas and denim.
The process uses large stones to roughen up the fabric being processed. The garments are placed in a large horizontal industrial clothes washer that is also filled with large rocks. As the wash cylinder rotates, the cloth fibers are repeatedly pounded and beaten as the tumbling stones ride up the paddles inside the drum and fall back down onto the fabric.