Logo: O Caderno de Aimé-Adrien Taunay - Histórias, descobertas e percursos
realização: Logo: IHF - Instituto Hercules Florence
apoio: Logo: Museu Paulista
Logo: O Caderno de Aimé-Adrien Taunay - Histórias, descobertas e percursos

DIGITALIZATION AND RESTORATION

Preservation of ferrogallic paint

The preservation of documents produced with ferrogalic paint is truly challenging, because there are many factors involved in the procedure, for example, the quantity of parts involved, the types of materials used in the fabrication of the support and the various physical-chemical processes that occur on the object. A characteristic of the documents that were written with ferrogalic ink is that deteriorate and weaken very quickly. The sheets become brittle in those places with a higher concentration of ink, which can lead to darkening and loss of the recorded information. Therefore, the continuous degradation of documents written with ferrogalic ink is something of special attention for the preservation of the written cultural heritage.

Preventive conservation is one of the main strategies for the protection of texts and involves a series of actions whose purpose is to slow down the degradation process. In this sense, it is important to have a storage environment with stable temperature and humidity, free of pollutants, an adequate placement and proper handling. Another widely used strategy the digitization of fragile materials, thus avoiding manipulation and further deterioration.

The treatment methods used to preserve documents endangered by ink corrosion aim at interrupting two basic deterioration mechanisms: the process of acid hydrolysis of the cellulose caused by the sulfuric acid present in the ink, and the process of cellulose oxidation catalyzed by the excess of Fe(II) ions in the ferrogalic ink.

In 1995, the Dutch chemist Johann Neevel developed a treatment in aqueous medium known as Calcium Phytate that hinders those two deterioration mechanisms and has an effective action for the stabilization of manuscripts in ferrogalic ink. Other studies have been developed for treatment in non-aqueous medium and also to treat large sets of documents.

Pages written with ferrogalic ink on paper. Photo: José Rosael.

Pages written with ferrogalic ink on paper. Photo: José Rosael.

realização:
IHF Museu Paulista
partnership:
USP IFUSP - Instituto de Física da USP NAP - FAEPH