Types of damage and restoration measures
Mould
Mould infestation occurs in connection with unfavourable storage and / or water damage. It can develop very quickly under special conditions, such as warm, humid rooms, and attack books to the point of destruction in a short time. Depending on the extent of the damage, the mould can be suppressed by various measures from brushing to irradiation. In the case of severe infestation, it is even necessary to decontaminate entire stacks. Optimal storage in terms of temperature and humidity prevents the spread of mould infestation. In case of loss of substance, the disinfected objects are subsequently restored to their original condition by hand by a restorer.
Ink erosion
Ink was generally made in earlier times on the basis of tinctures of gall and iron. The combination of these substances can react under poor storage conditions - warm, humid rooms - and release sulphuric acid, which attacks the paper or parchment written on, causes the writing to disappear and can even lead to holes. The objects must be individually deacidified by a restorer. Loss of substance is then removed by handicraft work.
Water damage
The penetration of liquid wears down the paper fibre and causes discolouration. The affected paper can easily tear and thus suffer further damage. Proper restoration of the objects can only be carried out after examining possible consequential damage (see mould, ink corrosion).
Unfavourable storage
The effects of high humidity and high temperatures are among the most important damage factors for books and bindings. In addition to the natural deformation of objects due to temperature and humidity fluctuations, bacterial infestation and chemical reactions can also be triggered.