THIS JUST IN: There is now a fundoshi page on Facebook.
Irezumi (also known as Horimono, or literally "body engraving") is a Japanese artform involving extensive body tattooing that the fundoshi is uniquely, um, suited for displaying. Long associated with criminality, and especially Japan's organized crime (the Yakuza), spectacular "waterfall" style tattoos can completely cover the arms, legs, shoulders, and buttocks, but often leave hands and feet blank and a wide, bare stripe down the center of the chest. That way, when normally clothed, the wearer's tattoos remain secret. The designs are usually taken from Japanese woodblock prints and traditional drawings, and can be quite detailed and richly colored. Often, it takes years to complete a full body-suit irezumi tattoo. For a long time, there was a ban on displaying tattoos in pubic that has been relaxed quite a bit in recent decades. However, many bath houses, hot springs and other businesses still prohibit tattoos, and participants in some of the winter Naked Festivals ("Hadaka Matsuri") are required to cover tattoos with bandages.
The first black & white photo below comes from reknowned Japanese photographer Tamotsu Yato's beautiful 1968 monograph, Naked Festival, and remains one of our favorite all-time fundoshi photos!
Of course, if you can't spare the time or don't think withstanding the pain is worth being clothed in a mural of resplendent ink for a lifetime, there's always this option:
So if you were to go under the needle, what would your irezumi depict?