"Hendricks develops color impact in various ways. In the self-portrait, the overall tone is shadowy, but he also did a series of white-on-white paintings in which dark skin color stands out graphically. Clothing and backgrounds are milky white in single or multiple-person images such as Steve (1976) and What’s Going On (1974). In an early example in the series, Dr. Kool (1973), the clothing of the uncropped but squeezed-in male figure with a dark briefcase is far more softly focused than the face and hands. A faded effect evokes a bleached photograph except that the face is distinct and realistic."

Janet Koplos, Art in America, February 24, 2009

The present photograph is the basis for the painting Dr. Kool, held in the collection of Dr. and Mrs. Robert and Joan Clark, Philadelphia. This was one of the few works by Hendricks that we have handled. It was a great and important early document by the towering figure in post-civil rights black art in America.