This was a commission by a local ad firm for something to cover the entire back wall of their office.  The wall was divided by two doors and a central beam, so a large map of Toronto seemed like a great way to unify the whole wall.  I pored over dozens of historical maps of Toronto from the late 1700's to modern day.  Elements from various maps were chosen to create a piece that was balanced - I wanted the main text, of the company's logo and the city, to be the focus.  "Throwing" or "pulling" the long strokes for the flourishes requires whole arm movements that must be quick and fluid.  I end up using both my left hand and right to create the flourishes; unlike ink on paper, if the flourish is uneven, or not fluid, the chalk can be erased and the stroke reattempted.