Original Post — Direct link
13 days ago - /u/JagexSponge - Direct link

Fun little explanation as to why this happens on some items:
Items essentially have code on them that runs when a different item is used on them.
If an item doesn't have any code assigned to it it'll run the default code which includes checks for notepaper functionality etc.

Other items that do have their own unique code can then return back to the default code after (this is what we see on things like herbs that can have potions/incense used on them but then also work with notepaper)

In the case of the wizard hat, it has its own unique code for working with black ink but then doesn't return to the default case.

We could realistically fix the majority of these notepaper issues - it'd just take some time to find them all.

12 days ago - /u/JagexSponge - Direct link

Originally posted by Deathcon4111

Is this why some items dont work with note paper if used on it but work when the reverse is done?

Eg. Item->notepaper does nothing

Notepaper->sameitem gets noted?

Yeah exactly

Originally posted by DPSOnly

Oh that is very interesting, I was wondering why rings of life (dropped by Onyx Dragons) couldn't be noted. I do wonder what the interaction is with that item that is blocking it, like the wizard hat/black ink one.

There is a jar in Curse of Arrav / Dimension of Disaster that you use the ring with :)