The Gutenberg Bibles were the first books printed using moveable type but are just as famous for their colorful illustrations. Now, UK researchers have used a non-invasive spectroscopic technique to identify the precise pigments used in the Gutenberg illustrations. The findings not only provide chemical data that might help conservationists, but could also provide new insights into the printing practices of fifteenth century Europe. "This represents an important first step in an appropriate conservation and preservation strategy," says study co-author Gregory Smith, formerly of University College London and now a professor of conservation science at Buffalo State College in New York. Raman spectroscopy has now revealed, for the first time, the exact chemical composition of the bright red color: cinnabar or its synthetic equivalent vermilion; the yellow is lead tin yellow (lead stannate); black is carbon; blue is azurite, (copper carbonate); white is calcium carbonate; olive green is malachite (another copper carbonate); and dark green is verdigris (copper ethanoate).
The colorful world of Gutenberg