The Environment Series[1][2] Heads developed from the Environment Triptych portrait sculptures by Jon Edgar in 2006. His ongoing series of terracotta clay portraits celebrates those contributing to a sustainable future on Earth. The sculptor observes the sitter on a rotating chair, working over seven or eight hours building up the head on a wooden peg using small pieces of clay.[3] One sitter accounted "It is the most intense and prolonged physical scrutiny I have ever had from a friend. For hours on end."[4]