Chemical analysis deciphers biblical palette.

Many copies of the famous Gutenberg Bible, printed in the 1450s, have decorative illuminations that artists added to the margins of pages. Researchers have now identified for the first time the various paint pigments that individual artists used to embellish these texts. The findings, outlined in the June 1 Analytical Chemistry, could guide future efforts to conserve the texts.

Conservation scientists at University College London and Buffalo (N.Y.) State College analyzed paint samples from seven Gutenberg Bibles in England, Germany, and France. Using a laser technique called Raman spectroscopy, the researchers identified 10 pigments in a copy that once was owned by King George III. For instance, the bright-red paint used to depict flowers and birds' plumages was a common pigment from that era called cinnabar.

Analysis of the other six Bibles showed that the artists relied on similar palettes, with a couple exceptions. The two German copies bore the expensive blue pigment lazurite, suggesting that the Bibles were intended for particularly wealthy owners. One of the German copies also contained the modern pigments known as anatase (white) and rutile (yellow). The presence of these pigments could have been the result of recent conservation treatments or contamination, the researchers say.--A.G.