<p>Scientists have discovered that Roman-era Egyptian mummy portraits used the pigment Egyptian blue, invisible to the naked eye, as material for underdrawings and for modulating colour - a finding never before documented.<br /><br /></p>.<p>Scientists and art conservators from Northwestern University and the Phoebe A Hearst Museum of Anthropology set out to investigate the materials the painters of 15 Roman-era Egyptian mummy portraits and panel paintings used nearly 2,000 years ago.<br /><br />What the researchers discovered surprised them, because it was hidden from the naked eye: the ancient artists used the pigment Egyptian blue as material for underdrawings and for modulating colour.<br /><br />Because blue has to be manufactured, it typically is reserved for very prominent uses, not hidden under other colours.<br /><br />"This defies our expectations for how Egyptian blue would be used," said Marc Walton, research associate professor of materials science and engineering at Northwestern.<br /><br />"The discovery changes our understanding of how this particular pigment was used by artists in the second century AD. I suspect we will start to find unusual uses of this colourant in a lot of different works of art, such as wall paintings and sculpture," Walton said.<br /><br />Before the Greek period, Egyptian blue was used everywhere throughout the Mediterranean - in frescoes, on temples, to depict the night sky, as decoration. But when the Greeks came along, their palette relied almost exclusively on yellow, white, black and red.<br /><br />"When you look at the Tebtunis portraits we studied, that's all you see, those four colours," Walton said.<br /><br />"But when we started doing our analysis, all of a sudden we started to see strange occurrences of this blue pigment, which luminesces.<br /><br />"We concluded that although the painters were trying hard not to show they were using this colour, they were definitely using blue," Walton said.<br /><br />The researchers studied 11 mummy portraits and four panel painting fragments. The 15 paintings were excavated between December 1899 and April 1900 at the site of Tebtunis (now Umm el-Breigat) in the Fayum region of Egypt.<br /><br />The fragile mummy portraits are extremely lifelike paintings of specific deceased individuals. Each portrait would be incorporated into the mummy wrappings and placed directly over the person's face, said Jane L Williams, a conservator at the Hearst Museum.<br /><br />The researchers uncovered the unexpected uses of Egyptian blue - the first man-made pigment, inspired by lapis lazuli, the true blue - using a routine battery of analytical techniques, such as X-ray fluorescence and X-ray diffraction.<br /><br />Six of the 15 paintings have the unusual use of blue, the researchers found.<br />The skilled painters employed blue for underdrawings, to modulate clothes and the shading on clothing. <br /></p>
<p>Scientists have discovered that Roman-era Egyptian mummy portraits used the pigment Egyptian blue, invisible to the naked eye, as material for underdrawings and for modulating colour - a finding never before documented.<br /><br /></p>.<p>Scientists and art conservators from Northwestern University and the Phoebe A Hearst Museum of Anthropology set out to investigate the materials the painters of 15 Roman-era Egyptian mummy portraits and panel paintings used nearly 2,000 years ago.<br /><br />What the researchers discovered surprised them, because it was hidden from the naked eye: the ancient artists used the pigment Egyptian blue as material for underdrawings and for modulating colour.<br /><br />Because blue has to be manufactured, it typically is reserved for very prominent uses, not hidden under other colours.<br /><br />"This defies our expectations for how Egyptian blue would be used," said Marc Walton, research associate professor of materials science and engineering at Northwestern.<br /><br />"The discovery changes our understanding of how this particular pigment was used by artists in the second century AD. I suspect we will start to find unusual uses of this colourant in a lot of different works of art, such as wall paintings and sculpture," Walton said.<br /><br />Before the Greek period, Egyptian blue was used everywhere throughout the Mediterranean - in frescoes, on temples, to depict the night sky, as decoration. But when the Greeks came along, their palette relied almost exclusively on yellow, white, black and red.<br /><br />"When you look at the Tebtunis portraits we studied, that's all you see, those four colours," Walton said.<br /><br />"But when we started doing our analysis, all of a sudden we started to see strange occurrences of this blue pigment, which luminesces.<br /><br />"We concluded that although the painters were trying hard not to show they were using this colour, they were definitely using blue," Walton said.<br /><br />The researchers studied 11 mummy portraits and four panel painting fragments. The 15 paintings were excavated between December 1899 and April 1900 at the site of Tebtunis (now Umm el-Breigat) in the Fayum region of Egypt.<br /><br />The fragile mummy portraits are extremely lifelike paintings of specific deceased individuals. Each portrait would be incorporated into the mummy wrappings and placed directly over the person's face, said Jane L Williams, a conservator at the Hearst Museum.<br /><br />The researchers uncovered the unexpected uses of Egyptian blue - the first man-made pigment, inspired by lapis lazuli, the true blue - using a routine battery of analytical techniques, such as X-ray fluorescence and X-ray diffraction.<br /><br />Six of the 15 paintings have the unusual use of blue, the researchers found.<br />The skilled painters employed blue for underdrawings, to modulate clothes and the shading on clothing. <br /></p>