For a long time, the exact material that was used to make these manuscript covers, called chemises, has remained unclear. Now, scientists subjected over a dozen of these book covers to diverse ...

A study published in the journal Royal Society Open Science ... on 19 books created between 1140 and 1275, the experts used mass spectrometry and ancient DNA analysis to determine the materials ...

which are materials that physically coat the substance, like dried mud on a Sunday dress. As such, the era’s most fashionable shade of green pigment could grace the covers of popular books.