The owner of Borhani Rug Co. in Timonium specializes in such carpets, which account for about three-quarters of his sales, but he has not been able to import any from Iran until now. He and other U.S. rug dealers relied on a supply built up before 2010, when the U.S. imposed an embargo on Iran. As supplies dwindled, many dealers have shifted to selling rugs made in India, Pakistan and China.