In medieval Iceland, lawspeakers remembered the laws of their society by heart. They used this knowledge to resolve disputes at the thing. In the course of the Middle Ages, however, laws were written down. Now, it turns out that the scribes thought carefully about the process. About which parchment to use for law texts to avoid falsification. New research shows that they chose the parchment that is the hardest to scratch and thus, to remove text from!
The academic article is in Open Access (see below), but there is also an fine read on Science News.
Doherty, S.P., Henderson, S., Fiddyment, S. et al., ‘Scratching the surface: the use of sheepskin parchment to deter textual erasure in early modern legal deeds.’ in: Heritage Science Volume 9.29 (2021). doi.org/10.1186/s40494-021-00503-6.