John Rackham, commonly known as Calico Jack, was an English pirate captain operating in the Bahamas and in Cuba during the early 18th century. His nickname was derived from the calico clothing that he wore, while Jack is a nickname for "John".

Calico is a heavy plain-woven textile made from unbleached, and often not fully processed, cotton. It may also contain unseparated husk parts. The fabric is far coarser than muslin, but less coarse and thick than canvas or denim. However, it is still very cheap owing to its unfinished and undyed appearance.