In addition to being used to describe a placard required for all vehicles registered in the state of California, the term “California license plate” is also used to discuss tattoos positioned on women's lower backs. Lower back tattoos are especially popular in California, which explains the origins of this slang term; there are also a variety of other colorful and less polite slang terms for lower back tattoos. In many communities, lower back tattoos are heavily stigmatized, as people draw conclusions about the morality and creativity of the wearer.
Positioning a tattoo on the lower back is actually quite sensible. The lower back provides a large canvas, creating room to work on a large project, and it is less prone to stretching and sagging, so a California license plate will not become distorted with age. Tattoos on the lower back also tend to stay crisper longer, because they are less exposed to sunlight than tattoos on the arms and legs, depending on the fashion trends followed by the tattoo's owner. The California license plate is also easy to hide with strategic garments.
The positioning of a lower back tattoo is also perceived as sensual by many people, especially when a tattoo is customized for the woman it is applied to. The lower back has a variety of sensual, flowing curves which can be accentuated with a well-designed tattoo, and this undoubtedly explains why many women perceive the California license plate as a “sexy” tattoo.
In the 1990s, the California license plate began to proliferate among young women, as tattoos in general became more socially acceptable. Lower back tattoos were especially common on actresses, cropping up regularly in film and television. As a result, many people began to deride such tattoos as prosaic and mainstream, and the idea that the California license plate indicates a loose woman began to proliferate. Some of the less charming slang terms for a lower back tattoo, such as tramp stamp, slut tag, strumpet trumpet, or bullseye reference the commonly held beliefs about the morals of women with lower back tattoos.
The California license plate has also been further maligned thanks to the fact that many women choose to get tattoo flash as lower back tattoos, rather than designing custom tattoos for themselves. Butterflies, fairies, flowers, Celtic knots, and pseudo-tribal designs tend to proliferate on the backs of young women in urban areas, leading to great derision, even when those symbols have a personal meaning to the wearer.
In fact, having a lower back tattoo says essentially nothing about your morals: a California license plate can appear on a devout Christian wife and mother just as easily as it can on a casually-minded sorority girl. For people considering a lower back tattoo, there are a number of ways to avoid or reduce the stigma of the California license plate. Off-centered tattoos often look much more visually interesting and less overt, for example, and a custom-designed tattoo can also help to create the image of a personalized and deeply meaningful tattoo. Especially big custom projects also tend to avoid being classified as “tramp stamps,” because they indicate a deep level of commitment and thoughtfulness.
Incidentally, this wiseGEEK author's favorite slang term for a lower back tattoo is the German arschgeweih, which politely translates as “posterior antlers.”