I read these two articles

https://www.newsinlevels.com/products/laws-on-vellum-level-1/

https://www.newsinlevels.com/products/laws-on-vellum-level-2/

Summary in English

Their laws are traditionally written on Vellum in the UK.
Vellum is made from animal skin.
Some people think that paper is a cheaper option, so they don’t like Vellum.
Vellum can last for 5000 years. Some people think that laws should be written on a long-term storage medium.
The Magna Carta (written in 1215) is a very important law.
It still exists in the UK and costs six pounds for every century.