Sand nude silk and organic cotton double breasted trench coat from Katharine Hamnett featuring a belted waist, a long length, an open collar and an oversized fit. POSITIVELY CONSCIOUS: Katharine Hamnett scores 4 out 5 by independent ethical brand rating agency Good On You. It uses some eco-friendly materials and low impact non-toxic dyes in all of its products. It manufactures locally to reduce its carbon footprint and does not use fur, leather or exotic animal skin.