Sailor tattoos are traditions of tattooing among sailors, including images with symbolic meanings. These practices date back to at least the 16th century among European sailors, and since colonial times among American sailors. People participating in these traditions have included military service members in national navies, seafarers in whaling and fishing fleets, and civilian mariners on merchant ships and research vessels. Sailor tattoos have served as protective talismans in sailors' superstitions, records of important experiences, markers of identity, and means of self-expression. Common symbols include swallows, nautical stars, and anchors. For centuries, tattooing among sailors mostly happened during downtime at sea, applied by hand with needles and tattoo ink made with simple pigments such as soot and gunpowder. These tattoo artists informally developed a graphical vocabulary including nautical images such as mermaids and ships. Starting around the 1870s, a few former sailors began opening professional tattoo parlors in port cities in the United States and England, especially after the development of the electric tattoo machine in the 1890s. In the United States, these former sailors trained a larger generation of professional tattoo artists. These artists developed the American traditional ("old school") tattoo style by combining sailor traditions with styles and techniques learned from Japanese tattoo artists. "Sailor tattoos" can refer to this style of tattoo, which was popularized for a broader audience starting in the 1950s. There are records of significant numbers of tattoos among US Navy sailors in the American Revolution, Civil War, and World War II. Many sea service members continue to participate in the tradition. History of tattooing While tattoo, from the Polynesian root "tatau," only entered English and other European languages in the late 18th century, European sailors have practiced tattooing since at least the 16th century.