 In 1999 he received the first Plowden Gold Medal, awarded by the Royal Warrant Holders' Association to recognise the most significant contributions to the advancement of the conservation profession.Garry Thomson made a significant contribution to Conservation science, Preventive conservation, and Art conservation as a whole with his publication ‘The Museum Environment’ first published in 1978, and revised in 1986.This book became the major source of information regarding recommendations for environmental conditions in museums around the world, and although the guidelines are no longer followed as rigidly as they once were it continues to be a significant guiding book for the discipline.