Traditionally, both Matses men and women had facial tattoos. Some even had tattoos on their chest or arms. To make the tattoos, they mixed the soot from burning copal (Protium copal) with the juice of genipap (Genipa americana) to make a black ink. The black ink was used to make tattoos by pricking with a palm thorn. The tattoos on their faces are said to be used in order to signify to others that the Matses are fearsome. At one time, nearly all the indigenous people of the Amazon had facial tattoos that identified their particular tribe. This was particularly true in tribes of Panoan stock from the Western Amazon.