ABSTRACT
The artistic and documentary contribution of manuscripts makes them unique evidence of ancient knowledge that we must protect through conservation. Most of the manuscripts of Europe and America are written with iron gall inks, documented from 4th century [1] to 19th century [2]. But in since the 17th century, scribes began to speak about the problems in ink conservation in ancient writings [3].
The Valencian archives conserve numerous documentary collections from the period after the Conquest, but those in the time period between 1450 and 1600 stand out by the deficient state of conservation.
For this reason, in depth study and characterization of the ink components have been analysed in relation to their state of preservation. Given the high iron content of these inks, we also find impurities of copper and zinc. A systematic study of 989 micro-samples has been carried out, and the iron/copper/zinc concentration ratio results were evaluated; the samples are not homogeneous and the proportion of ink in the paper could change, and the filament values could also be different depending on the dates and the archives to which the micro-samples belong in the semi-quantitative results offered by SEM/EDX analysis.
A statistical study was carried out using an ANOVA analysis of iron/copper/zinc concentration as a function of the archive. The concentration of iron/copper/zinc was analysed according to the date in which there is an observable increasing trend of deterioration between the thirteenth and seventeenth centuries. These values relate to the incorporation of new organic and inorganic ingredients in the preparation of recipes, as well as the differences in preparation and concentration of iron/copper sulphate according to the solvent used.
The integrated study of historical sources and elemental analyses help to recognize both the materials and the state of conservation, which facilitates the process of conservation and restoration.
