Calcium-phytate / calcium-bicarbonate method

1. INTRODUCTION
The calcium-phytate / calcium-bicarbonate method was first suggested for treating ink-corroded manuscripts by Neevel in 1995. Since then, several international projects focussed on the efficiency and the side–effects of this method (Kolar et al. 2005, Kolbe 2004, Tse et al., 2005, Zappala and De Stefani 2005, Botti et al. 2005, Hofmann et al. 2004, Jembrih-Simbürger et al. 2004, Reissland and de Groot 1999). All studies agree that the calcium-phytate / calcium-bicarbonate method is an effective aqueous method to prolong the life-time of ink corroded objects with minimal side effects. However, conservators feel uncertain to actually apply this treatment method. Typical questions arising are: Can I prepare the treatment solutions in my workshop? Where can I purchase the necessary chemicals? What is the precise sequence of treatment steps? The aim of this chapter is to provide paper conservators with all information that is necessary to treat ink-corroded objects with the aqueous calcium phytate / calcium bicarbonate treatment method.

  
Please bear in mind that this chapter focuses on single-object treatment, rather than on mass–scale treatment. Scaling up a treatment to mass-scale approaches requires a thorough optimization of the treatment process, especially on wetting and drying procedures. Mass scale approaches usually accept more undesired side effects than single-object approaches.

BE AWARE: For unique items like manuscripts and drawings written or drawn with iron gall inks, risks and benefits of any treatment action should be thoroughly compared in order to make an informed decision. We are explicit on the fact that after an aqueous and non-aqueous treatment, most information that is inherent in the artefacts material is irreparably lost. Be aware that such treatments completely change both the ink and paper composition. Analysis of ink and paper composition that provides scientific data for dating, provenience, authorship or other comparable questions can not be carried out after such treatments anymore since it generates incorrect results. Therefore, a decision for preventive measures, local treatment and minimal intervention should always be a preferred alternative to any aqueous or non-aqueous treatment of an entire artefact!

Contact:
Karin Scheper, University Library, Leiden
Sabine Fleischer, Broekens & Fleischer – Book and Paper Conservation, Nijmegen
Birgit Reissland, Netherlands Institute for Cultural Heritage (ICN), Amsterdam