In the field of paper conservation, there are a myriad of challenges that one can encounter. Some of the biggest issues that arise when treating works of art on paper are the result of fragile media and temperamental fibers within the sheet. “Works on paper were intended for daily use and handling, and thus do not stand the test of time as well as other art forms that were meant to be admired from a distance,” said Brian Kapernekas, The Conservation Center’s Senior Paper Conservator. “Many of the conditions we encounter are not only related to age, but also to improper storage.” Acid-free and archival housing materials are relatively new in the scope of framing practices. Most people do not even realize that acidic materials are usually the cause of the gradual deterioration of paper—until it is too late and the sheet is heavily yellowed, embrittled, and the damage is too severe to reverse.
The treatments that works on paper undergo at The Center’s laboratory are specifically tailored for each individual artwork. These can be quite extensive and time-consuming depending on the stability of the media and the length of the fibers in the paper. It is paramount to stabilize the substrate and to consolidate as much of the original media as possible. “We assess each work by first removing the work from its frame, housing, folio, or binding, so that a thorough condition report can be performed,” said Brian. “Then, we determine the type or types of media used and the composite of the paper, followed by some research on the piece. If necessary, selective testing might be done as well to construct an individualized treatment method.”
A great example of this process was recently undertaken on a 16th century engraving by Albrecht Dürer (1471–1528), entitled St. Sebastian at the Column (1500). The work is an impressive piece from Western Illinois University’s (WIU) extensive art collection that depicts Saint Sebastian, an early Christian Saint being shot with arrows—a common depiction of his martyrdom. Dürer captures the intensity of the moment in his characteristic style. During his career, Dürer excelled as a printmaker, mathematician, painter, and theorist. His catalogue of work—a unique blend of influence between the Italian Renaissance and German Humanism—has led to him being widely regarded as one of the finest artists of the Northern Renaissance.
WIU’s St. Sebastian at the Column exhibits extensive foxing, which is visible in the small, brown circular stains throughout. Foxing is caused by many different factors that each require radically different treatments, so it is important to always precisely identify the source before proceeding. Some of the causes of foxing are: the presence of mold spores at the time the paper was made; particulates within the framing package; housing that may have accelerated the development of age-related discoloration; and even rust from small metal particulates, such as iron fillings, which are embedded within the fibers of the sheet. These gradually oxidize over time resulting in small circular stains. In this particular sheet, test results showed that the foxing was mainly a result of non-archival housing-related issues that had accelerated the natural aging process of the sheet. Additionally, there were a few instances of minute iron deposits visible within the paper fibers under a microscope.
The sheet also had two fills that were hidden under the hinges. A fill is when an area of loss is backed with a small segment of paper that is similar to the original in tone and composite. These are usually adhered using a reversible adhesive such as wheat starch paste. These fills were done to conservation standards as there was no visible appearance on the face of the sheet less some slight evidence of compensation, also known as retouching. There was also a small, weakened area in the paper fibers at the upper right corner, just below the paper fills.
From the information gathered during the original assessment, Brian developed a customized approach to treat this print. First, he selectively cleaned the surface of the print in order to remove any dirt or particulates that could have built up over the years. The hinges (tabs of adhesive-backed paper on the verso used to mount the work during framing) were then removed using appropriate methods; it was at this stage that the fills became visible. The iron deposits were removed mechanically (by hand) under a microscope. After all of these preparations were made, the print then underwent stain reduction treatment, which, in this case, involves the submersion of the print in filtered water. Once the paper began to “relax,” the sheet then underwent part two of the stain reduction treatment—it soaked in buffered solutions. This process required multiple applications of the buffered solution. The duration of treatment for this print was contingent upon the degree of foxing as well as age of sheet all while ensuring the integrity of the pre-existing paper fills were maintained. The print was then transferred to a bath of filtered water before being prepared for drying. The sheet was slightly air-dried and the weakened area on the verso was reinforced with a thin patch of Japanese tissue and wheat starch paste. Weights, cotton blotters, and interleaving were used to further reduce distortion and stabilize fibers during the drying process.
“The blotter drying process involves a time-sensitive progression that requires the blotters be changed repeatedly over a period of time to ensure the removal of excess moisture,” Brian adds. “This has to be done quickly and efficiently as any moisture left from the stain reduction treatments will cause distortion within the sheet, resulting in a rippled, wavy artwork. Our constant attention during the drying process protects the artwork from becoming distorted after treatment.” After the sheet was thoroughly dried, we compensated select areas in the pre-existing fills with watercolor pencil to help integrate any inconsistency.
Once St. Sebastian at the Column was successfully treated, Brian made a final assessment before The Center’s Custom Framing department protected the print with archived housing materials and Tru-Vue Museum Glass that is anti-reflective and blocks out 99% of harmful UV rays. The delicate nature of this Durer masterpiece was indeed a challenge for our paper conservator, however, we were gracious for the opportunity to treat such important piece from the Renaissance era.