Pencil
A box of pencils of varying grades is a joy to me. Going from the hard H's with their lighter greys to the blackest of black B's...can't beat it! And somehow all that beautiful stonework we're so lucky to live close to here in Orkney whether it's thousands of years old neolithic, 19th/20th century crofts hugging hillsides or simply sea- smoothed stones on the shore - all work well with a graphite rendering.