The moment I finished my perusal of Man with a Blue Scarf by Martin Gayford my first reaction was that it should be made compulsory reading for anyone asked to adjudicate in future on Australia’s annual Archibald Prize. For what Gayford describes in considerable detail is the prolonged process of sitting for a portrait by the man considered by many to be the world’s pre-eminent living artist, Lucian Freud. The book thus goes a long way towards explaining what outstanding portraiture is really about. Freud is a relentless and fastidious practitioner whose purpose is to reveal the inner as well…