.5 Pencil
This is an industrial city viewed from above. I do this for fun. It evolved from doodles during study time in school. I used .5 mechanical pencils for this, and went through a lot of lead. This example here is one of many. This was a large piece which required multiple scans of different areas to then be assembled together as one image in Photoshop. Another example of this kind of scanning and stitching is below.