The Jagiellonian University Paper Clinic is a specialised ‘health centre for books’. A part of the Jagiellonian Library, this unique laboratory preserves volumes of significant importance.
The Paper Clinic was born out of the work of Prof. Andrzej Barański from the JU Faculty of Chemistry Laboratory for Paper Durability and Degradation. Aside from restoring historic books, its team focuses on researching the causes and course of paper degradation, methodology of accelerated aging tests, and evaluation of the techniques for large-scale paper deacidification.
We asked the Paper Clinic’s head, Dr. Arkadiusz Knapik, to tell us more about this very peculiar line of work.
A book goes to the doctor
Books haven’t always been published on durable parchment. What might come off as a paradox is that old books – those issued before, let’s say, 1850 – had higher chances of surviving until now than the ones issued after that. Why? Well, the middle of the 19th century marked the spread of the technology of paper production in an acidic environment, which leads to long-term degradation of cellulose chains, causing the paper to break down.
In the face of an increasing risk of irrevocably losing a great number of invaluable books, the JU Paper Clinic was established at the Jagiellonian Library in 2006. Every day, its experts fight to save books by suppressing acid degradation and returning them to their original condition, preserving their contents for as long as possible. The scope of their work is not limited to the Jagiellonian Library – in fact, they receive books from all across Poland, collaborating with such institutions as the National Museum in Kraków, Cieszyn Library, Adam Mickiewicz University in Poznań, and POLIN Museum of the History of Polish Jews.
Because of that constant stream of books, the Paper Clinic bears some similarity to a real medical facility. Every day, the Clinic takes a delivery of volumes in urgent need of treatment, and so they usually have to spend some time in queue before they are admitted. Although the process of mass deacidification allows dozens of books to be processed simultaneously, it’s estimated that so far the treatment was successfully completed for only 10% of the collection of the Jagiellonian Library alone.
Printing press – blessing for people, curse for books
Paper owes its mechanical properties to its main constituent: cellulose. This compound is a linear biopolymer composed of many particles of glucose chained to one another by glycosidic bonds. The more cellulose there is in a chain, the better properties a piece of paper has. Up until the late 18th century, cellulose in Europe was produced by pulping linen cloth, and then turned into laid paper. In the 19th century, increased demand for paper resulted in the first paper machines. About mid-19th century, linen cloth was replaced by wood pulp. ‘Cellulose chains in paper produced from linen were very long. It made them strong and durable. Wood pulp forms shorter chains, which means that paper made from it has poorer quality’, explained Dr Knapik.
To prevent ink from running all over sheets of paper, they needs to be sized. Initially, people used gypsum, flour gruel, and even gelatine. ‘Starting in the mid-19th century, paper makers began utilising alum(-K) and then aluminium sulphate for that purpose. It was cheap and readily available. Unfortunately, when the latter of the two dissociates, it releases a large amount of hydrogen protons into the environment (in this case: paper), which in turn accelerates the process of acid hydrolysis of cellulose, shortening its chains. We could say that aluminium sulphate “cuts” the already short wood pulp cellulose chains and causes the paper to deteriorate more rapidly’, he added.
It’s estimated that around 97% books published before 1996 stored in Jagiellonian Library are printed on acidic paper. Sizing of paper in an alkali environment, introduced en masse in Poland in the 1990s (partly thanks to the efforts of conservators), has successfully decreased the problem of passive paper deterioration. 15 years ago, experts assessed the number of books in the Jagiellonian Library in need of deacidification at 1.5 million. However, the lack of specialist centres prevented its management from saving them. ‘It’s worth to emphasise that paper is the most universal form of storing information. To access it, one needs only to be able to read. It doesn’t require any viewers or scanners. It seems that won’t change for quite some time’, said Dr Knapik. It’s therefore good to be aware of effective paper preservation techniques.
New technologies for relics of the past
To easily asses the acidity of paper and thereby identify its risk of deterioration, we can use acid-base titration: employing solutions which leave a mark that changes colours based on the pH of paper. A chlorophenol red solution applied to acid-free paper will leave a purple mark, while on acidic paper it will appear yellow.
Currently, the most widely used solution for book conservation is the Bookkeeper Deacidification Process, invented in the USA in the 1980s and generally recognised as the most effective method of preserving books. Books are placed in a special deacidifying reactor for about 3–4 hours. The reactor is flushed with perfluoroheptane carrying magnesium oxide. ‘Perfluoroheptane evaporates, while magnesium oxide gets rid of hydrogen protons responsible for acidic environment, effectively neutralising it and removing the threat of degradation’, explained Dr Knapik. The books are then vacuum dried and returned to their owners.
The JU Paper Clinic is the first of its kind in Poland and one of several in the world. It's a unique institution which contributes to saving the legacy of our civilisation and preserving it for the future generations.
Photograph: Paper Clinic
Original text: www.nauka.uj.edu.pl