Navy blue silk satin Nicola shirt from Katharine Hamnett featuring a classic collar, a front button placket and long sleeves. 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.