A painting of a woman on lime wood is one of the mummy portraits being studied by researchers using special camera filters under different light wavelengths (left to right: visible, ultraviolet, and infrared) to identify pigments and binding agents.(© The Trustees of the British Museum)
More than 1,000 mummy portraits, painted on wood panels or cloth shrouds between the first and third centuries A.D., are in museums today. In the late nineteenth and twentieth centuries, archaeologists uneart