whistler worked in various art forms,including etchings and lithographs.However,he is most famous for his paintings'particularly Arrangement in Gray and Black No.1:Portrait of the Artist's Mother or Whistler's Mother,as it is more commonly known.This painting shows a side view of Whistler's mother,dressed in black and posing against a gray wall.The asymmetrical nature of the portrait,with his mother seated off-center,is highly characteristic of Whistler's work.