An ATR-FTIR and ESEM study on magnetic tapes for the assessment of the degradation of historical audio recordings

This article presents some approaches for chemical and physical characterization of materials (ATR-FTIR and ESEM) applied to a specific category of cultural material, magnetic tapes. Analogue recording on magnetic tape has been the main technique for capturing sound for about five decades in the past century. Most of our collective memory is therefore stored on this type of medium, which is unfortunately degrading very fast. The past twenty years have witnessed a true rush to digitization in order to save the information stored on tape, but many aspects of the physical recovery of damaged carriers are still performed without solid scientific knowledge, leaving space for improvised treatments with unexpected ill effects. The main motivations for this study are that the preservation of sound recordings is an urgent matter that belongs to the field of Intangible Cultural Heritage preservation, the scientific literature on the subject is scarce and little known by the non-scientific archival world, and the documented approaches to tapes recovery are currently fragmented and do not provide an exhaustive reference for the operators in this field. The analyses presented in this article aim at paving the way for the establishment of a scientific protocol for the safe recovery of damaged tapes.