Peeling back the past: Sheepskin delamination and patch repairs in parchment

The ability of sheepskin to delaminate has been exploited in the production of Late Antique manuscripts, offering the advantages of high-quality parchments and patch repairs. This study investigates delamination in sheepskin parchment using Scanning Electron Microscopy (SEM) and micro-Raman spectroscopy. By analysing a sample from experimentally produced lambskin parchment, this research identifies the delamination site within the skin structure and explores the bonding process of patch repairs. SEM imaging suggests involvement of the papillary dermis in the delamination. Micro-Raman spectroscopy indicates removal of epidermal layers and a portion of the papillary dermis during peeling. Wetting dynamics experiments with ferrogallic ink shows differences in absorption between delaminated and non-delaminated surfaces. The adhesion of patch repairs demonstrates stronger bonding in intentionally applied patches compared to accidental adhesion. This research clarifies the reasons for sheepskin parchment’s susceptibility to delamination and provides insights into traditional repair techniques and the material’s surface properties.