Prison ring

A prison ring is a type of plastic jewelry fashioned by hand in prisons, by working scrap plastic material, commonly celluloid items such as a toothbrush or a pen.^[1][2] Celluloid was historically a popular material since it could be heat bonded and glues were often less available.^[3] A common feature of prison rings were small photos mounted on the bezel.^[3]

The rings were produced as early as the 1920s. Rainey Bethea, the last person to be publicly executed in the United States, was caught after a 1936 rape and murder because he left a distinctive prison ring at the murder scene.^[4][5]