20 years ago, in college, I worked at the uni library's special collections department. One of the things we would do was check leather-bound books for 'red rot', which is when the tanning of the leather starts to fail, and the leather starts crumbling to produce this really characteristic red dust. It's treated with a product called cellugel.

I told my parents about this cool job.

'Oh,' they said, 'can you do something about this old book from your great-grandmother's collection?'