Tattoos have also been used for identification in other ways. As early as the Zhou, Chinese authorities would employ facial tattoos as a punishment for certain crimes or to mark prisoners or slaves. During the Roman Empire, gladiators and slaves were tattooed: exported slaves were tattooed with the words "tax paid", and it was a common practice to tattoo "Stop me, I'm a runaway" on their foreheads. Owing to the Biblical strictures against the practice, Emperor Constantine I banned tattooing the face around AD 330, and the Second Council of Nicaea banned all body markings as a pagan practice in AD 787.
Sleeve tattoos are a collaboration between a tattoo artist and customer to demonstrate a personal and unified artistic theme. Other times, a sleeve is created when a person has many smaller tattoos on their arm and later has them connected with background tattooing to form a sleeve. Planned sleeves generally require many long hours of tattooing and can take weeks, months or years to complete.
Mainstream art galleries hold exhibitions of both conventional and custom tattoo designs, such as Beyond Skin, at the Museum of Croydon. Copyrighted tattoo designs that are mass-produced and sent to tattoo artists are known as "flash", a notable instance of industrial design. Flash sheets are prominently displayed in many tattoo parlors for the purpose of providing both inspiration and ready-made tattoo images to customers.