Issues of paper permanence for long-term documentation and knowledge transfer to future generations

Mankind is known to be curious and inquisitive. Even if the code was lost, future individuals would be eager to find out what kind of message a printed paper offers. This already was the case when the hieroglyphs were deciphered. Printed paper doesn’t need additional equipment to be recognised as a data carrier. Therefore, paper as an analogue data store medium is an interesting redundance (to digital, microfilm or other medium) to deliver important information to future generations. The presentation deals with topics of age-resistance of paper and inks as well as recommendations how to empower printed or written paper to be a long-term data store. Different ageing conditions, different inks, different printing processes and different fibre sources reveal the opportunities and threats. Data obtained during a 2-year lasting project together with German Federal Authority for the Disposal of Nuclear Waste (Bundesamt für die Sicherheit der nuklearen Entsorgung – BASE) on long-term stability of paper – Labest Papier – emphasize the feasibility. The ageing mechanisms of paper are known, as are countermeasures. This leads to standards and recommendations for the use of paper for documents. ISO 9706 is the main proponent of the direction that longevity can be ensured solely via the composition of the paper and the initial situation at the beginning of ageing. DIN 6738, on the other hand, takes as its basis the approach of assessing the physical ageing of the paper based on artificial ageing and the strength losses observed in the process. Other standards vary the approaches somewhat or mix them in part, for which the lecture presents a comparison table. The usability of a document depends on two essential factors. Firstly, the residual strength after an ageing process must be high enough for the document to be usable. Secondly, the information written on it must still be legible or at least recognisable. However, although certain fibre resources are recommended by different standards dealing with long time storage of documents as well as some fibre sources are denied, we must consider that all fibre sources undergo an ageing process. Different combinations of fibre and ink will lead to different results after natural or artificial ageing. This doesn’t necessarily mean that only the best combination is able to fulfil the requirements related to transport information to an address in the far future. Albeit less strong or with higher optical changes, even by actual standards rejected fibre source may nevertheless be able to keep the printed in-formation over a long period of time. Paper is a proven reliable information carrier for appr. 1,000 years as the eldest known paper document archived in Palermo is from 1109 AD. It is reasonable to expect a reliability for many more years, because the papyrus “Evers” (worldwide longest, complete and best-preserved papyrus scroll) stored at the University of Leipzig is already 3,500 years old. Compared to modern information storage media such as digital media or microfilm, paper also has the advantage of a long migration time and that no reading or decoding device is necessary. Taking this into account, paper documents are predestined to play a major role in record, knowledge & memory (RK&M) strategies, as described by Pescatore et al. (see link in bibliography). Final remains to say that there can never be an intactness in the sense of being completely untouched. Paper, however, is a material consisting of natural polymers that prove their longevity in the world's oldest tree, a 9,500-year-old spruce in Sweden.