A closer look at the Azzolino collection

The state of preservation of documents from the historically significant Azzolino collection at the Swedish National Archives has been investigated and analyses carried out of the iron gall inks. The collection shows varied levels of iron gall ink corrosion. An initial visual condition survey was followed by characterisation of the writing ink with XRF spectrometry on a selection of documents. The aim was to investigate whether ink composition could be related to author or geography, and in turn to level of ink corrosion, which could then serve as a basis for decisions on treatment options. Results indicate a relative purity of the inks in this collection in terms of high iron content and low levels of other elements, entailing that elemental analysis is not a good tool to predict potential deterioration of ink in single documents from this historical context. XRF-mapping showed a possibility for discerning authors by ink composition, contributing meaningful information to questions of attribution and historical context for these documents. A tendency for the ink of Queen Christina to contain more copper than inks from the other authors, and the indication that some inks contain calcium, may be of note for further study.