Mason first began serious artistic pursuits when he arrived at the UW in 1938. "I did them [watercolors] so easily and everybody has so much trouble with watercolor."The most attractive properties of watercolor for Mason were the same that made the medium difficult to master: fluidity of paint and permanence of each brush stroke. For Mason, watercolor allowed him to improvise, sketching and at the same time painting the final composition. Though his teacher and mentor Hill exemplified how to properly paint landscape, Mason’s pursuit of watercolors steadily moved away from his own small controlled landscapes to larger, free-style abstractions.
"With their audacious color, surprising scale, and exuberant abstraction, they represent a break with the drably colored or poetic narratives that had typified painting here following the advent of the Northwest School… In the paintings titled the ‘Burpee Garden’ series Mason produced six by seven foot paintings in a color range not previously seen in the Northwest. Created from 1970 to 1976 this short period produced some of the most influential and groundbreaking works ever made in Seattle."
By the 1970s Mason had abandoned white backgrounds and began his work by painting black over the entire canvas or sheet of paper, then proceeding with the rest of his painting. This process gave the desired pop to the brilliant acrylic colors he was using. The artist began chopstick drawings on black grounds and followed with drawings of softer colors during the Squeeze Bottle period. Mason's drawing at this time took on a different feel also, as he began testing with oil sticks washing his marks with turpentine and smudging them to create a filmy watercolor feel
2013 – death