In discussing the painting technique of the 19th century American landscape painter, George Inness, a brief description of Inness' three major style periods is included along with a summary of pubiished technical descriptions of his work. While concentrating primarily on ten Inness paintings in the collection of The Cleveland Museum of Art, which span more than forty years of his career, paintings from other collections have been examined for comparative information. The investigation covers a detailed study of each painting, including microscopic and infrared examination, and x-radiographs. Correlations are made between Inness' style, materials, and his painting technique. Distinctions in his major style periods are further clarified by the varying technical phenomena observed. In addition, a continual concern in studying works by Inness is that of authentication. Some observations are made concerning the different tech niques used in his work and in those purported to be by him.