Later in life Dunn remarked: “The most fruitful and worthwhile thing I have ever done has been to teach.” Dunn became an influential and revered teacher; students referred to him as “Mr. Dunn” as a sign of respect and admiration. The majority of Dunn’s students were either graduate level painters or professional illustrators. Dunn was not interested in teaching painting techniques. His approach was philosophically oriented—he spoke about spirit, emotions, and discourse at length. He discussed his philosophy of life and art, offered group criticism, and strode from easel to easel discussing each student’s work in turn.