Project Overview & Authors

Handmade paper constitutes the primary repository for human records made in Europe between the early fifteenth century and the beginning of the nineteenth century. Much remains to be learned about its production and distribution—testimony in itself to the ubiquitous nature of paper and how routinely it was taken for granted then and perhaps still is today. But close analysis of the papers themselves can often shed new light on a particular historical episode or figure. For example, when letters from a particular writer are found on especially poor-quality paper given the writer’s time and place, it may indicate something significant about her financial situation. When a book is printed on very high-quality paper for its period and location, it may suggest something new about the publisher’s intended audience and marketing strategy. Both instances provide evidence that would be wholly lacking in digital scans of the same pieces of paper. Beyond the possibility of new historic insights from the physical evidence in paper, the material selection and workmanship evident in the best papers are awe inspiring to the modern-day hand papermaker or conservator. These subtleties in handmade paper are worthy of our attention today. Paper does more than support words or images. It can bring alive its own moment in history or show us how to make longer lasting paper in the future. That potential constitutes a window well worth looking through. And better access to that portal is what inspired this research.

Writing and printing papers of a wide range of quality were made at many locations and times throughout the period this study focuses on.  The superior longevity and stability of some papers and the rapid decline of others have intrigued paper researchers for generations. The W. J. Barrow Research Laboratory’s 1974 analysis of 1,470 papers made between the sixteenth and the twentieth centuries demonstrated that early, well-preserved papers were made from pure cellulose (rags), were neutral or slightly alkaline in pH, contained an alkaline reserve (likely calcium carbonate), and were sized with a non-acidic material. The research also demonstrated that the analysis of long-term naturally aged papers provides valuable information that impacts conservation practice and the manufacture of modern handmade and machine-made archival papers. The Barrow work was based on technologies that required destruction of parts of each paper sample and as a result, exceptionally stable but rare fifteenth century papers were excluded from the study. We felt the development of nondestructive analysis techniques, allowing the inclusion of fifteenth-century and earlier papers, made possible a similar but new study that could reveal useful information about paper stability and aesthetics and be valuable to paper historians and conservators.

In the fall of 2010, we completed a new analysis of 1,578 papers using only nondestructive techniques. Book, manuscript, and printmaking papers made between the fourteenth and the nineteenth centuries were tested using XRF (X-ray fluorescence) and UV-Vis-NIR (ultraviolet-visible-near-infrared) spectrometers. For each specimen, we gathered data on gelatin and alum concentration; calcium (Ca) and iron (Fe) concentration (in whatever form they appeared, such as oxides, salts, or metal fragments); color; sheet dimensions and thickness; paper strength; publication (date, title, author, country, etc.); and quality of materials and workmanship. We photographed each item and, for some of the specimens, judged the likelihood that they had been washed or resized. We also tracked whether the same book contained sheets with differing grades of materials and workmanship. All research methods and results of the study are included in this website. Some details on the development of instrumentation and techniques have been published or are forthcoming in cited journals. This work was made possible by funding from the Institute of Museum and Library Services, The University of Iowa, and the Kress Foundation, with additional support from several collaborating institutions.

We found that the fifteenth-century European papers we tested had higher gelatin and Ca concentrations than papers made in subsequent centuries. They were also thicker and lighter in color (CIE L*a*b*–value equivalents). Other plots indicate that superior materials and workmanship were generally associated with higher levels of gelatin and Ca, lighter color, and lower levels of alum and Fe.

We also studied the ability of three technologies to nondestructively monitor paper characteristics during conservation treatment: XRF to estimate concentrations of Ca, Fe, and alum; and ultrasonic and/or UV-Vis-NIR to predict paper-strength properties.

We believe our data will be of value to conservators, conservation scientists, paper and book historians, and manufacturers of papers intended for archival or conservation applications. As in the Barrow Research Laboratory study, conclusions about any single variable’s contribution to the stability of historical papers must be borne out by subsequent accelerated-aging studies using laboratory-prepared paper samples.


Cite as: . "Project Overview & Authors." Paper through Time: Nondestructive Analysis of 14th- through 19th-Century Papers. University of Iowa. Last modified . .