I have a painting That was painted by someone by the name of Riggs who apparrently studied in New York and Paris and developed a unique abstract expressionist style of vibrant color and heavy impasto for a sculptural feeling. Apparently he has had one-man shows in New York, Chicago, San Francisco, and Paris. I am wondering about his history and Life as an Artist. The painting is my Grandfathers he bought it in the early to mid 1970's. Is there a demand for his art.