The house flag of John Stewart and Co. Shipping, Glasgow. A red rectangular flag with a black diamond in the centre and a white border bearing the white letter 'S'. The flag is made of a wool and synthetic fibre bunting. It has a cotton hoist and is machine sewn. A rope and toggle is attached.

In 1910, Scottish broker John Stewart began his foray into the ship owning business by purchasing the ship ‘Corundum’, which subsequently sank in 1914. In 1923 he purchased the ship ‘Yewdale’ and spent the rest of that decade establishing his business. Stewart purchased war surplus engines and enlisted the help of the shipbuilding company Scotts of Bowling based in West Dunbartonshire, Scotland to build coasters which contained these engines. These coasters were finished between the years 1928-1931, and were used in transporting coal along the east coast of England, specifically along the Thames in London and areas in northern France. Finally in 1934 John Stewart Company Shipping Limited was incorporated. Two years later, however, John Stewart died and the company was purchased by Ian and Edgar Macfarlane. In 1939 the company purchased its first motor ship. During World War II the company was still active in the coal trade. It survived until 1979, when it was acquired by Carita Investments of Scotland and traded under the name John Stewart until 1991 when the company dissolved. (Research: Rebecca Hernandez).