hubby's been wearing these for years.  Last year ordered the denim color that have slightly less wool contente and they shrunk up really bad and we sent them back to hanes/duofold and were promptly issued a refund.  We've never had a problem before.  I don't put them in the dryer for more than a couple minutes and then I hang them on a rack to dry.  He wears these daily all winter long to work.  A pair usually lasts him for years before they wear out.