Castle's contributions as an artist, sculptor, designer and educator were instrumental in the establishment of the American decorative arts movement and the recognition of handcrafted, designer furniture as a major art form. He was acknowledged as the leading figure in American studio furniture movement in the 1960s and '70s, and he continues to lead this field, evolving new standards for craftsmanship. His pieces are crafted from rare hardwoods, plastics and metals as well as other materials, and they feature color, texture and innovative finishes and laminations. He is both a sculptor and technician.
Castle has been honored with a Lifetime Achievement Award for Excellence in Design by the Brooklyn Museum of Art, recognized by the Renwick Alliance of the National Museum of American Art as a Master of the Medium, and designated as a Visionary of the American Craft Movement by the American Craft Museum. His pieces are included in all major collections of American art, including the Metropolitan, Renwick, American Craft, Cooper-Hewitt, Crystal Bridges and Brooklyn museums, the Art Institute of Chicago and the White House, and they are prized by private and corporate collectors.
The Emporia native's work embodies the highest standards for art and design; his work has inspired students and instructors to create objects that are both practical and beautiful. He received a Bachelor of Fine Arts in industrial design, as well as a Master of Fine Arts in sculpture in 1961 from the University of Kansas.