These are fantastic inks, but caveat emptor, although they advertise themselves as document/waterproof inks they do have a soluble component. This means that if you put a wet or sweaty glass on top of your page it will smear badly enough to be unreadable.
If it gets truly wet then there is definitely a permanent part of the ink, but my problem is usually that I splash my page or spill something accidentally when I'm writing in notebook at the same time as having a cup of coffee. For this purpose the ink is close to useless as a "permanent" ink.
They are wet and beautifully colored inks that lay down really well. They take a bit longer to dry than some of the standard inks (Sheafer blue/Quink etc), but are much better than some similar wet inks.