Ever wear jeans fresh from the store and notice your hands and shirt turned blue? When dye is transferred by friction, it’s called crocking, and the indigo dye in blue jeans is a notorious crocker. Before you leave a tint of blue everywhere, the laundry is your first stop. Wash with cold water and, before the rinse cycle starts, stop the machine and add two cups white vinegar and soak. After a couple of hours, turn the machine on to finish. Hang and air dry your jeans, then press with the hottest iron setting. Then throw them back into the machine for one more cold-water wash.