A tattoo is an ink design added into the skin, generally with the help of a needle. This procedure has prehistoric roots, it has been used by people for thousands of years, in various forms. Examples can be seen in the majority of human cultures, and despite some societal stigma, tattoos are getting to be ubiquitous in the West, with an estimated 25 percent of American people are wearing at least one by the end of the twentieth century.
Half-sleeves or quarter-sleeves are tattoos that cover only part of an arm, usually above the elbow, but can also be found below the elbow. A sleeve implies complete tattoo coverage of a particular area, so a half sleeve is a tattoo that covers the entire upper or lower arm. A "quarter sleeve" usually covers the area of skin from the shoulder midway to the elbow.
In 2017, researchers from the European Synchrotron Radiation Facility in France say the chemicals in tattoo ink can travel in the bloodstream and accumulate in the lymph nodes, obstructing their ability to fight infections. However, the authors noted in their paper that most tattooed individuals including the donors analyzed do not suffer from chronic inflammation.
The Japanese word irezumi means "insertion of ink" and can mean tattoos using tebori, the traditional Japanese hand method, a Western-style machine or any method of tattooing using insertion of ink. The most common word used for traditional Japanese tattoo designs is horimono. Japanese may use the word tattoo to mean non-Japanese styles of tattooing.