The painting materials and drawing techniques of a pair of two-panel folding screens entitled Red and White Plum Blossoms by Ogata Korin, a national treasure in Japan, were investigated directly and nondestructively by XRF, X-ray radiography, and high resolution digital imaging. Several assumptions were made about the materials used in the red and white plum trees drawn on the right and left screens, respectively, and the river drawn at the center. By the present investigation, the materials used for the paintings were revealed, and some of them contradicted what have been previously believed.