I found a tutorial on how to make type on a wall that is actual growing moss. And I just had to try and do it.
I used moss that was growing in our garden, so I'm not too sure if this will actually work, but I'll just have to wait and see! I found the tutorial here:
If this works I will upload more photos when it starts growing.
Sorry for the bad quality of the pictures, my camera hasn't been treating me that well :(