After about eight decades of use, the approximately 42,000 files are showing various degrees of wear and tear. In addition to that, their acidic paper is at risk of accelerated decay, which can be slowed down only through chemical treatment. In order to preserve the historical documents and to enable their digitisation, the two conservators examined each one of the sheets (more than a million) and stipulated restoration and conservation measures. The cleaning, deacidification and restoration of the files are carried out in batches at the Leipzig Centre for Book Conservation (ZFB).
Preparation and Restoration of the Documents
Condition Assessment at the Landeshauptarchiv
The serial assessment of the files provides a detailed overview of the existing damage and therefore allows the precise definition of the necessary restoration and conservation measures. The following data was recorded during the assessment:
- Number of sheets
- Are the sheets stapled together or are they bound?
- Which of the files contain material that requires special treatment?
- Oversized formats
- Mechanical damage, e.g. tears, paper loss, folded sheets, adhesions
- Time required for the cleaning and removal of damaging materials
- Weight of the files
- Packaging requirements
Most of the paper was machine-made in the 20th century and its acidity is gradually destroying the files. In order to slow down this process the documents have to be deacidified. Due to the large number of files, they cannot be restored and deacidified in-house. The archive has therefore assigned the necessary services to the ZFB after a Europe-wide tender.
By measuring the degree of acidity in the paper (pH-value) of randomly selected files as well as the amount of mould spores on their surface, the conservators are monitoring the success of the measures taken by the ZFB.
Restoration and Deacidification
At the ZFB, harmful materials such as staples or self-adhesive tapes are removed, tears are being mended and bindings are taken apart if necessary. Documents, which are not suitable for deacidification, are separated from the process. Following this preparation, the files are treated with a deacidification liquid, which penetrates deep into the paper and neutralises the acid.
After digitisation, the files will return to the Landeshauptarchiv, where the conservators will carry out a final assessment to ensure that the files are prepared in the best possible way for archival storage and future use.
Following this final quality management, the files will be repackaged into archival boxes made of suitable material, which will ensure the long-term preservation of the files. The files will then be placed in the archive’s repository and will be ready for use in the reading room.