Histological study of sheep skin transformation during the recreation of historical parchment manufacture

We report a simple histological study on skin biopsies from young domestic sheep following each step in transformation from skin to parchment production. During the recreation of historical parchment manufacture, histological analyses were conducted; before and after lime treatment, hair removal, and stretching. Sections were fixed and stained using a variety of histological stains to identify the presence of different molecular classes and the fibrous proteins, collagen and elastin. The results reveal surprisingly few histological changes in most steps in the production process. However, very visible changes in the supramolecular ordering of skin macromolecules (elastin, collagen) occur during the final stage of parchment production when stretched on the frame. Collagen fibres and hair follicles were all strongly re-oriented in the direction of strain. Surprisingly despite the thinness of the lambskin and the exhaustive treatment in lime, not all fats were saponified and even in the final product Oil Red O stained fat bodies were detectable on the hair side of the skin. We believe this study will help compensate for the lack of sources on microscopic changes in parchment during the recreation of its historical manufacture.