Joya was a printmaker, mixed media artist, and a former dean of the University of the Philippines' College of Fine Arts. He pioneered abstract expressionism in the Philippines. His canvases were characterized by "dynamic spontaneity" and "quick gestures" of action painting. He is the creator of compositions that were described as "vigorous compositions" of heavy impastoes, bold brushstrokes, controlled dips, and diagonal swipes".Joya added the brilliant tropical colors. He was awarded a Fulbright-Smile-Mundt grant which enabled him to pursue a master's degree in Fine Arts in 1956-57
His works were strongly influenced by the tropical landscapes of the Philippine Islands. Among his masterpieces are the Nanking (a collage rendered with Asian calligraphy and forms and patterns resembling rice paddies), the Granadean Arabesque (1958) and Biennial (1964).
^Endaya, Imelda Cajipe (artist and independent curator) and Cecilia B. Rebong (Philippine Consul-General). "Pamana: Modernong Sining" (A Heritage of Modern Art), An Art Exhibit from the Collection of the Philippine Center in New York, Printed Catalogue, The Consulate General of the Philippines, Philippine Center Management Board, and PCGNY.net, June 11, 2007, page 10