I am building a fantasy world where one of the main characters gets ahold of a beautiful dwarven-made map.
The remarkable thing about this map is that it is not made by a cartographer, but rather by an artist who encountered a dying cartographer at the opening of a great mine. The cartographer gave his notes to the artist, also a dwarf, who was so fascinated with the mine and the treasure that was said could be found there that he was inspired to make the map.
It is not necessarily the most accurate map, but it serves the purpose of helping the main characters find the hidden treasure.

At the moment I am trying to figure out what the map might look like. To help me do that I am also trying to figure out what the notes that the artist was given were like.
  • Were they a bunch of numbers and codes that represented measurements of rooms and tunnels?
  • Were they carefully drawn sketches of the architecture?
  • Were they rough sketches of an actual map?


Since I have no idea how a cartographer works, I don't know what type of material the artist would have been given to work with.
Is there anyone who can give me some tips?