I did some fade tests with several pens and a pencil on a laser print. The pencil and toner were the only things that hadn’t faded in direct sunlight after two years. Even high end pens faded.
To be fair, your notebook probably won’t get light like that, but pencils are pretty archival.
Interesting. I wonder if in 100 years time Stephenson's fountain pen writing will still be around. No doubt they are all scanned, but, maybe the originals will fade.
I saw another video about someone's favourite pen and he gave the reason as check fraud. Apparently the uniball 207 is pigment based ink and doesn't wash away in acetone.
I just searched then on youtube for acetone pen check fraud and it looks like there's a 13 year old video about it, and a million copycats. Either copycats are lazy, or the 207 is still $2 13 years later.