IOWA CITY – University of Iowa researchers have uncovered “secrets” that may change the way manufacturers make modern paper.

According to a news release, Timothy Barrett, director of papermaking facilities at the UI Center for the Book, led a team in examining more than 1,500 historical papers from between the 14th and 19th centuries.

The three-year study found that older papers held up best over the years due to higher levels of calcium and gelatin, according to the release.

“The research results will impact the manufacture of modern paper for archival applications, and the care and conservation of historical works on paper,” Barrett said in the release.

Although  paper materials are increasingly viewed in digital form, Barrett said in the release that paper materials will continue to be produced and preserved as “essential” back ups to digital scans for centuries to come.

For example, the release said Barrett and the UI papermaking team worked with the National Archives staff in 2000 to create handmade paper for the Archive Rotunda in Washington DC.

In addition to the study’s impact on papermaking, the findings shed light on the context of many historical documents, the release said. For example, if a paper was poorer quality, researchers could better guess the author’s financial situation.

The team included Irene Brückle, professor at the State Academy of Art and Design in Stuttgart, Germany, Mark Ormsby, a physicist at the National Archives and Records Administration, Jennifer Wade from the National Science Foundation, Michael Schilling and Joy Mazurek from the Getty Conservation Institute, and Robert Shannon from Bruker Elemental.

UI team members included Joseph Lang, a professor of statistics and actuarial science, and Jessica White, a UI graduate student.