Sark is the smallest of the major Channel Islands, about 80 miles south of England and 20 miles west of France. A ferry ride from Guernsey, or a fast catamaran from Jersey, and you land at the Maseline Harbour on Sark. Sark may be a tiny island, less than two square miles in size and with only 550 inhabitants, but it has all the essentials, like television and telephones, and a single post box in front of the Post Office where Guernsey stamps are sold.
The Sark Stamps were issued by the Commodore Shipping Company stamps for the small parcel service between Guernsey to Sark in the Channel Islands. Less than 200 stamps were issued over almost 20 years, where printing quantities of 10,000 were not unusual. No more stamps can be issued as the shipping contract ended 30 September 1969 with the start of the Guernesy Post Office.
In 1971, a number of 1967 G-S definiatives were overprinted in red or black at the same time of the British Postal Strike [BPS] for the World Jamboree held in Japan. These overprinted stamps had no connection with the Guernsey-Sark Commodore Shipping service.
For more information:
Guernsey-Sark OnLine Stamps Catalogue