Yeah, it's called a pencil.
We have letters from a World War One soldier in our family. The paper is fragile and browning, but the pencil writing still holds up!
I must have been thinking of this thread when I stood outside of a store today, waiting for my husband. There was a little pencil on the ground, and I snagged it.
I need me one of those ‘Carpenter’s Pencils’.
http://www.youtube.com/watch?v=GAsSOnU0jqk