This paper describes the application of atomic force microscopy (AFM) for the imaging of collagen denaturation as\udobserved in parchment. Parchment is prepared from processed animal skin and collagen is the main component. Large\udcollections in national archives, libraries and religious institutions contain numerous documents written on parchment.\udTheir preservation presents an unsolved problem for conservators. The main challenge is to assess the state of collagen\udand to detect what conservators refer to as the pre-gelatinised state, which can cause surface cracking resulting in a loss\udof text and can increase the vulnerability of parchment to aqueous cleaning agents. Atomic force microscopy (AFM) was\udfirst used within the Improved Damage Assessment of Parchment (IDAP) project, enabling the characterisation of the\udcollagen structure within parchment at the nanoscale. Damage categories were also established based on the extent\udof the ordered collagen structure that was observed in the AFM images. This paper describes the work following the\udIDAP project, where morphological changes in the fibres due to both artificial and natural ageing were observed and\udlinked to observations made by AFM. It also explores the merits and drawbacks of different approaches used for sample\udpreparation and the possibility of using a portable AFM for imaging directly on the surface of documents. A case study on\uda manuscript from the 18th century is presented.
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