The Future of Preservation

It felt like completing the first leg of a mountain climb. At the international Preservation in Perspective conference, which was held both online and in person at Berlin's James Simon Gallery, on 23 and 24 November 2021, the stakeholders involved in the founding of the Coordination Office for the Preservation of Written Cultural Heritage (known by its German abbreviation KEK) began by looking back proudly on how far they had already come. Since the Coordination Office was established a decade ago, politicians and the public have been successfully sensitised to the importance of preserving original written materials. To date, the KEK has supported 850 projects with a total of €18.4 million and catalysed further preservation efforts.

"Preserving cultural property has become a higher priority", said Johannes Kistenich-Zerfaß, Director of the Hessian State Archives, at the opening of the conference. The federal and Land-level budgetary resources allocated to this work roughly doubled from 2012 to 2021, he estimated. "That is a fantastic achievement." And yet this sum is only about a third of the €63.2 billion required to conserve at least one percent of the written cultural heritage in the originals per year, the KEK's stated target in its 2015 National Recommendations for Action. With that, the focus at the international conference quickly turned to the path ahead.

Core questions that beg answers

Kistenich-Zerfaß outlined the challenges currently facing preservation stakeholders. How can they harness resources sustainably? On a concrete level, which holdings should they conserve or restore first? What role should preservation play, given the overwhelming trend towards digitising cultural and written heritage? These two core questions intensively occupied the more than 250 participants over the course of two days. "Digitisation must not come at the expense of the original", Kistenich-Zerfaß declared. Neither should digitisation and preservation be pitted against each other. Instead, because objects must be in good condition to be digitised, there are obvious synergies at play when applying for public grants.

Still, a certain undeniable tension hangs in the air. This was evident at various moments of a joint talk by two representatives of the Swiss National Library: André Page, head of the preservation unit, and Agnes Blüher, a chemist who oversees paper deacidification. The two of them shared their experiences with the bulk deacidification of library holdings. Even though this process was once hailed as a flagship preservation effort and has delivered overwhelmingly positive results over twenty years, large-scale mass deacidification in Switzerland has now been discontinued as of June 2022. The associated "papersave swiss" plant could no longer be operated at a profit. Digitisation competes for the same financial resources, although this is also a question of how a given institution sets its priorities. Public archives, libraries and collections have a basic obligation to respond to changing use patterns. Today's users are increasingly at home in the digital realm, and their familiarity with hands-on media formats now takes second place, explained chemist and cultural studies scholar Matija Strlič from the University of Ljubljana. Without a doubt, those trends make providing digital access to collection holdings imperative.

However, the example of Finland demonstrated what a protracted and complex task the mass-digitisation of archives entails.  The Finnish National Archives are tasked by law with digitising the written materials of all public authorities. Some 130 linear kilometres of the material meet the criteria and are slated to be digitised within the mass digitisation process. A disposal concept has been developed to phase out paper records, reported Ville Kajanne, head of the Production Unit in the Service of Mass Digitisation. In future, only around two percent of official written materials will be retained in analogue form according to current estimates.

Digitisation versus preservation? 

This comprehensive shift from analogue to digital formats raised numerous questions at the conference: Which originals will be preserved in analogue form? How certain can anyone be that the originals are no longer necessary? "It is primarily documents from the past forty years, which were created digitally before the authorities filed them, that are now being converted back into digital form", Kajanne clarified in the discussion, laying out the Finnish National Archives' position unambiguously. "The digital representation is a document, not a copy." The authorities will retain all documents considered to be cultural heritage, textual materials on unusual substrates and holdings that are too fragile to be scanned. "This is always a case-by-case decision taken by the public authority in question."

The mass digitisation effort in Helsinki was preceded by a pilot project. It furnished many lessons, Kajanne said. "Starting off with the procurement of scanners: Do they truly provide the image quality the manufacturer claims? Can they scan both sides of a page at the listed speed?" If the scanning process goes too slowly, digitising all the documents can take many decades. It is also crucial for the scanning process to halt automatically in the event of an error, a feature that these devices do not necessarily provide out of the box. The Archives were only able to purchase turnkey software for the scanning process itself. The requirements for subsequent data processing were so specific that a programme was custom developed for that stage.

Beyond that, mass digitisation is by no means an automatic procedure. Some 30 employees work at the department, Kajanne explained. A series of manual checks and automatic processes across several checkpoints verifies that the digitised versions are legible, complete and identical to the paper original. In addition, each document is bar-coded to ensure that it is always logistically traceable and that "total chaos does not erupt", Kajanne said. After the initial quality check, the archival JPG file is used to generate additional files, such as a lower-resolution version for users and a file with the bibliographical details. The 21 scanners currently process two linear kilometres per year. Even at a plausible rate of nine kilometres per year, it would take 14.5 years merely to digitise the central government agencies' written records that are eligible for mass digitisation. Having presented this calculation, Kajanne contended: this rate is a political decision. Digitising more quickly would raise the immediate costs. In terms of the whole project, however, it would decrease expenditures.

Kajanne sees many advantages in mass digitisation. Files can be made accessible to users with just a few clicks. In the past, citizens needed to take arduous trips across the country to view such documents. "With artificial intelligence, it will be possible to comb through the data in the future and draw entirely new conclusions," he put forward. "That’s the next step." Yet the usefulness of a central digital archive to the broader public depends on the quality of its metadata, as librarians and archivists have long been aware. From that perspective, the dichotomy between original and digitised version begins to blur.

Non-invasive measures must be prioritised

Binary categorization into analogue versus digital formats is inadequate for other reasons as well. This was vividly demonstrated during a talk by Oliver Hahn, head of the Department of Artistic and Cultural Property Analysis at the Federal Institute for Materials Research and Testing. He specialises in the spectroscopic analysis of cultural objects, a technique allows employees to see inside objects without destroying them. The resulting digital spectrograms provide digital metadata that can furnish valuable knowledge, which occupies a grey area between the domain of an original and a conventional digitised version. Hahn's working group has discovered sketches beneath the surfaces of paintings by Rembrandt and others. Based on spectrograms, employees at the Berlin laboratory and its cooperating institution, the Klassik Stiftung Weimar, realised that the head in the drawing An Old Man Reading by Ferdinand Bol had been copied from Rembrandt's Man with a Beard. This raises new questions about the painting’s origins, which art historians can seek to answer.

The origins and chemical composition of a given ink, chalk or paint can also be revealed using a combination of X-ray fluorescence spectroscopy, multispectral image analysis and infrared reflectography. "What we generate are new metadata that must absolutely be associated with the original and stored together with it", Hahn argued. He went so far as to say, "These metadata can open doors to much deeper insights than are available to the naked human eye viewing the original. Yet the original is and remains the unique object that must be preserved under any circumstances." Spectroscopic metadata can also play a decisive role for restoration. Only after performing this sort of non-destructive analysis can specialists determine whether a document's discolouration was caused by ageing or, for instance, a previous repair. Yet in Hahn's view, these spectroscopic methods are not only a sort of magnifying glass for cultural property. They are also suitable for large-scale use.

Software-based solutions for preservation

Together with on-site colleagues, he is currently undertaking a systematic analysis of the extensive holdings of the Klassik Stiftung Weimar. "Particularly for works by 'second tier' artists, this offers us the most compelling insights into their origins and the painting techniques of a given period." Each scan takes just a few seconds, he said. Another takeaway from the conference was the need for more large-scale procedures, especially innovative ones. This was necessary, the participants felt, to preserve and manage the sheer quantity of valuable cultural property – on a tight budget. Currently, even the available funds cannot always be fully disbursed due to insufficient capacity among service providers, Johannes Kistenich-Zerfaß dolefully observed.

Alongside bulk scientific procedures such as mass deacidification or spectroscopy, software-based solutions also fall into preservation's purview. One such procedure was presented by Michael Fischer, an employee at the Subject Indexing division at the Baden State Library. The staff there optimised their digital records for situations in which multiple deposit copies exist across various locations, enabling them to make an informed decision as to which copy they should preserve on site, deacidify and eventually digitise. The data model for this records optimisation scheme was developed in the framework of a KEK pilot project. The programme manages both the efficient division of tasks and preservation efforts within the same application. This approach can be rolled out to the dispersed holdings of deposit copies in other German Länder. Ulrich Fischer, Deputy Director of the Historical Archives of the City of Cologne, presented a bulk process for digitally piecing together the so-called "Cologne flakes," which were salvaged after the 2009 collapse of the archive building. The paper fragments are now being reassembled under a legal mandate. The company MusterFabrik Berlin developed a software package with associated special scanners that are supporting the archive team's endeavour of puzzling together the three million scraps of paper over the coming years. This technique can also be used to process Gottfried Wilhelm Leibniz’s shredded notes, Fischer explained, as an example of this bulk process’s value. 

Making decisions with data models

The role of IT-assisted solutions within preservation has grown over the years, particularly when it comes to data models that assist conservators with decision-making in regard to both damage prevention and restoration. Floriana Coppola, a chemist from Matjia Strlič's working group at the University of Ljubljana, offered an example from her current research. She has created a simulation of the deterioration of three hundred books dating from the fourteenth to twentieth centuries at the historic Classense Library in Ravenna, Italy. Based on her model's calculations, she determined that if the books are stored at sufficiently low humidity and a reduced temperature, they can be preserved for at least 600 more years. The library then adjusted its storage conditions accordingly. Modelling and more international cooperation between the research institutions, laboratories, and the entities funding cultural property collections would improve the quality of preservation, Strlič stressed. Cristina Duran Casablancas of the Amsterdam City Archives and University College London supported this call for greater interdisciplinarity.

No matter the quality of the simulations, there will always be imponderables and surprises. The centuries-long mission of preserving cultural property for posterity despite limited resources is visibly impacted by the earth's changing climate and climate protection policy. On the one hand, libraries and archives need to reduce their energy consumption. In Denmark, for example, they are committed to a target of climate-neutral operations by 2050. Marie Vest, head of the preservation department at the Royal Danish Library, reported that today, a newly constructed archive is already using renewable sources such as solar and geothermic energy to minimise greenhouse gas emissions. Chris Woods, Director of the UK's not-for-profit National Conservation Service, considers the trend towards passive storage to be an additional climate-protection measure. He shared some of his own investigations demonstrating that storing holdings in climate-controlled spaces or mechanically reducing indoor air humidity was not always necessary. If the rooms were sufficiently sealed off from the outdoors and the holdings themselves did not contain too much moisture, it was sometimes possible to switch off climate control without causing damage to the cultural property, he said. Interestingly, the energy consumption of digitisation efforts is currently not emphasised. "But collecting the data and operating the computers consumes quite a lot of energy", Strlič pointed out during the concluding discussion. Logically, the electricity to operate digital archives must also derive from climate-neutral sources. A green analogue archive can only have a green digital sibling archive, Vest asserted. Scandinavian countries were early to recognise the climate policy dimension of preservation. "There, cultural heritage is incorporated into climate protection policy", says Johanna Leissner, a chemist and the chair of the EU’s OMC expert group "Strengthening cultural heritage resilience for climate change". "Not so in Germany, however." In her view, the implications of climate change for cultural property remain to be quantified.

Climate change and preservation

For example, the dangers posed by torrential rain and heat waves are still highly uncertain. Although movable holdings such as books and audio recording media stored indoors are less at risk because they can be moved to safety and are protected from the direct effects of the weather, they too face heightened threats in the future. For example, simulations project that a rise in the annual average temperature could cause a drastic increase in mould and mildew. Insect infestations in archives could also become more common, Leissner says. Institutions that wish to counter such threats with climate control must contemplate the growing energy needs. Last but not least, Leissner points out the indirect impact of climate change: if disasters cost money, there may be less available for other concerns. The competition for financial resources sharpens. There is an atmosphere of scarcity.

The point is always to maintain all options for future generations whenever possible, asserted Jacob Nadal, Director of Preservation at the United States Library of Congress. Cultural heritage holds a significant symbolic value that extends far beyond its monetary value. For that reason, too, books have always been politicised, whether in wartime, when they have been seized and scrapped, or during the Nazi era, when they were burned. Richard Ovenden of the Bodleian Libraries at the University of Oxford brought to life the pricelessness of written materials in his evening lecture. Archives and libraries preserve societies' knowledge. As storehouses of memory, they offer unique insights into millennia of cultural history. Only by preserving cultural heritage will we be able to access these irreplaceable perspectives.