Fayum mummy portraits
The wax encaustic painting technique was described by the Roman scholar Pliny the Elder in his "Natural History" from the 1st Century AD. The oldest surviving encaustic panel paintings are the Romano-Egyptian Fayum mummy portraits from Egypt around 100–300 AD, but was a very common technique in ancient Greek and Roman painting. It continued to be used in early Byzantine icons but was effectively abandoned in the Western Church.