Prison tattooing is the practice of creating and displaying tattoos in a prison environment. They are often used to portray gang membership,and are often used as a form of code and have hidden meanings.
Since tattooing in prison is illegal in the United States, the inmates do not have the proper equipment necessary for the practice. This forces inmates to find ways to create their own tattooing devices out of their belongings. Improvised tattooing equipment has been assembled from materials such as mechanical pencils, magnets, radio transistors, staples, paper clips or guitar strings. The ink used also needs to be improvised, either taken from pens or made using melted plastic, soot mixed with shampoo, or melted Styrofoam. Prison tattooing is not generally done freely, and the tattooists are normally paid with anything from stamps and cigarettes to actual cash.
There are many different symbols and numbers that represent multiple gangs or groups. Certain images like spider webs and teardrops can represent the length of sentences, or the number people that the wearer has killed, respectively. Tattoos are also used to communicate who the inmates are as people.
Here are a few examples of prison tattooing, showing the inmate (and potential inmates) BEFORE and AFTER.