This section is from the "A Complete Dictionary of Dry Goods" book, by George S. Cole. Also available from Amazon: A complete dictionary of dry goods and history of silk, cotton, linen, wool and other fibrous substances,: Including a full explanation of the modern processes ... together with various useful tables.
Guernsey (Gern'-Sy). [Named from having been first worn by the sailors inhabiting the island of Guernsey, in the English Channel]. A close-fitting, knitted woolen shirt, worn by seamen, sometimes called a guernsey-frock; similar to a cardigan jacket or jersey, except that it is a heavier and longer garment.