Modern library conservation was born in the aftermath of a catastrophic flood in Florence, Italy on November 4, 1966. Water from the Arno River devastated the collections of the National Central Library of Florence. An international team of bookbinders and restorers was assembled to save what they could; however in many cases the damage was irreversible. Many lessons were learned, and new procedures and protocols were established to prevent such disastrous loss from occurring again. Most importantly, the bringing together of esteemed professionals in their fields to deal with the results of the flood propagated the field of library conservation forward. Continued growth and research over the last 52 years allows us to do our work today with the greatest confidence.
Thankfully, we do not have to save collections from catastrophes every day. Instead we focus on slowing down the natural aging of materials to prolong their life. Ironically, one way to reduce acidic degradation products in paper is to submerge it in water. The water we use in the conservation lab is of course far removed from the dirty flood waters of the Arno River. For treatment purposes we use purified, de-ionized water, conditioned to a neutral pH. While it seems drastic and counterintuitive to submerge a piece of paper in water, the procedure is not completely out of place when we consider the role water plays in paper production.
Historically, old cotton rags would be cut into small pieces, soaked, and beaten to separate the fibers. The resulting pulp slurry would be cast out on a wire mesh known as the paper mold. The wet paper sheet would be then transferred to a felt and stacked with other sheets. Excess water would be squeezed out of the stack of paper with a heavy duty press, allowing the fibers to interlock, forming a strong piece of paper once dry. When the cotton fiber is in contact with acidic materials, such as gelatin sizing that was added to the paper, or even surface dirt, it starts to break down the cellulose building blocks of paper. Dry cleaning and washing reduces the acidic components in the paper, therefore prolonging its life.
This print of the Hudson River–“Palissades naturelles de l’Hudson,” from Jean B.G. Roux de Rochelle’s, Etats-Unis d’Amérique (Paris: Firmin Didot Freres, )–has yellow discoloration overall from contact with acidic materials in its old frame. The bottom right corner has a tide-line formed by uncontrolled contact with water. The acidic degradation products found in paper moved with the incoming water and were deposited at the boundary between wet and dry paper.
At the New-York Historical Society Library, the goal of a conservation treatment is to slow down natural deterioration of materials, rather than restoring items to a pristine condition. In the case of Palissades naturelles de l’Hudson washing the print reduced the amount of acidic components in the paper making it slightly brighter as a result. The tide-line in the lower right has been reduced, but not completely erased. Due to its location, the stain would not be visible if the item is called for exhibition because it would be covered by a mat. Complete removal of such embedded stains is not always possible and further reducing it would require use of toxic solvents. Such techniques would only be employed if the stain was disfiguring to the central image.
The catastrophic flood in Florence has shown us the importance of our work as conservators. Although we work behind the scenes and our work is not readily visible, we share these stories with the public to inspire interest and support for the preservation of our shared heritage.
This post is by Katarzyna Bator, Assistant Conservator.