Stonewashing 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 stones As the wash Stonewashing 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 stones As the wash