From Ripton:
Wash to tighten, wear aggressively.
Ripton denim is a miracle of modern science, but it’s still mostly cotton. Wear it often, and it will conform to your body and stretch out. Washing your apparel won’t necessarily “shrink” it, but it’ll regenerate the fabric to how it fit when new. It’s the ciiiiiircle, the circle of liiiiiiife.
Chill out, don’t wash your Ripton with hot water.
Stick to your washing machine’s cold cycle, or use an old-timey washboard in your sink.
On the subject of dryers, what’s the rush, people?! Let your denim air-dry, or if you must, use the lowest setting on your dryer.