Currently, there are twenty-nine different notes for writing in foreign languages learned from the scattered Language Dictionaries.
However, these notes are not very versatile. They are just pieces of paper that lay flat on a surface. You can’t post them on a wall like the arrow and dagger pinned notes.
Adding any new variations on these would be adding twenty-nine more objects though, which is pretty ridiculous.
I would instead suggest that a new button be added to the bottom of the scroll interface:

This interface would be shared across all objects that can be written in. All journals, scrolls, and every type of note.
Clicking on the Language button would bring up a language option window, allowing one to change the language of the text into any language the player has learned. Something like this:

I’m no expert, but I believe adding a simple language variable to writable objects shouldn’t be very difficult.
Obviously, the buttons for any language not yet learned would be grayed out and unselectable.
This would not only allow players to write in foreign languages in any writable object, massively expanding the versatility, but it would also make it much easier to write in foreign languages rather than having to search for and craft a specific note in the Artisan Table.