J.W.S. Cox is known for having first "invented" and explored the full possibilities of the wet-on-wet watercolor technique, the technique of painting on water saturated paper.

Cox was born on May 18, 1911 in Yonkers, New York, the son of an architect and his wife. He grew up in Bruynswick and Wallkill, New York, and from an early age sketched landscapes. He graduated from Pratt Institute in New York City (1933), while working at various jobs during the Great Depression.

From 1928-1936 Cox studied the works of El Greco for composition, Feininger for design, Turner for color and Cèzanne for style and brushwork, John Marin for composition and color, Marsden Hartley for design, Whistler for technique and Charles Burchfield for style and subject matter.