Even before the widespread use of paper in Medieval Europe, craftsmen utilized an unknown special technique to produce parchments. Now, about 700 years later, an international team of experts unraveled the mystery surrounding the large-scale publishing industry during the pre-Gutenberg era.
Medieval scribes managed to create ultra-thin sheets used as pages that were 0.03 mm to 0.28 mm thick, researchers said. The parchment is called "uterine vellum," and some scholars believe that as several sources made use of the Latin term abortivum, the skin of unborn calves were used to produce the vellum. However, other scholars dispute the theory.
This is why experts sought to find an answer behind this mystery. Led by scientists at the University of York, a group of bioarchaeologists wanted to know the true origins of these medieval parchments.
In a study featured in the Proceedings of the National Academy of Sciences, researchers developed a non-invasive method to identify the animal source of the parchment. By gently rubbing a PVC eraser on the surface, electrostatic charge was generated and it enabled the team to extract protein from the page.
"We found no evidence for the use of unexpected animals; however, we did identify the use of more than one mammal species in a single manuscript, consistent with the local availability of hides," explained Dr. Sarah Fiddyment, lead author of the study.
The findings suggest that the tissue-thin vellum was the result of making skin from adult animals such as adult goats and adult sheep look like the skins of newborn calves, researchers said.
Scientists carried out a series of tests on 72 pre-Gutenberg bibles which were made in numerous areas of medieval Europe. They discovered that 68 percent of these parchments were made of calf skin. Many bibles from France and probably some from England were under this category. Around six percent of the parchments were made from adult sheep. These bibles were mostly from England. Lastly, about 26 percent of the bibles were crafted from adult goats, and they were produced chiefly from Southern France and Italy.
In order to create these parchments, scientists said that medieval craftsmen drenched the animal skins into alkali-rich liquefied lime to get rid of the fats and by transforming the lipids into some form of detergent. This helped make the skins become ultra-thin, as well as dissolve all the ingrained stains and grime. Medieval artisans knew the precise time to thin and whiten the skins, because overexposure to lime would turn the skins into gelatin, the team said.
Professor Matthew Collins, director of the research project, said the findings of the study contributed to the understanding of the perspective of early publishers, as well as how these lightweight parchments played their role in the development of the continent's first universities.
"This has enabled us, for the first time, to more fully understand the birth of Europe's first commercial book production industry," added Collins.
