Walton was perhaps the most consistent of all the 'Glasgow Boys.' Although much in demand as a portrait painter, he was a landscape artist by inclination. Latterly Galloway became his favourite painting ground, due in part to the travel restrictions occasioned by the First World War. He was issued with a Defence of the Realm Permit Book in July 1917, enabling him to paint within a radius of five miles of New Abbey and Carsethorn until the end of October that year. A similar permit was issued by the War Ministry the following year, allowing him to work within five miles of New Abbey and Douglas Hall.