Rare books covered with seal skin hint at a medieval trade network

Science is helping researchers judge books by their covers — and revealing surprising beneficiaries of medieval trading routes in the process.

Dozens of rare, fur-covered volumes from 12th and 13th century French monasteries are wrapped with seal skins that may have come from as far away as Greenland, researchers report April 9 in Royal Society Open Science. The findings challenge the assumption that the books’ makers used only locally sourced materials and suggest that they were part of an extensive trade network.