His work is held in the permanent collections of many institutions such as the following: the Corcoran Museum, the Smithsonian American Art Museum, the Library of Congress, the New York Public Library's Schomburg Research Center in Black Culture, the Yale University Art Gallery, Brown University's John Hay Library, Howard University's Founders Library and the University of Maryland's David C. Driskell Center.

Platt is a graduate of Columbus College of Art and Design and Howard University. He teaches at Howard University and is represented by International Visions - The Gallery.