The play between external and internal forms dominates Lipton’s later work. His characteristically massive, textured pieces twist, curve, and seem frozen on the verge of opening. They are frequently suggestive of and titled after animals and plants.
His commissioned works include sculptures at Philharmonic Hall at Lincoln Center, New York City (1964), and Dulles International Airport, Washington, D.C. (1964).(Encyclopædia Britannica)