Homage to the First Principal, two 13th century Taoist Chinese wall paintings in the collection of The Royal Ontario Museum (ROM), recently underwent extensive analysis and conservation. In the early part of this century, the paintings were cut into numerous small blocks and taken from China to Japan. There, the support material was removed and the paint layer mounted onto paper and muslim panels, six to each painting. The panels were brought to New York and acquired by the ROM in the 1930's. In Toronto, the paintings were mounted onto masonite, three sections for each of the six vertical panels, thus totaling eighteen masonite panels per painting. The panels were then screwed onto mahogany grids and mounted onto walls in the museum. The 1980's conservation treatment attempted to resecure the numerous support layers without disturbing the adhesives and materials used in previous treatments, remove surface dirt, discolored resins, overfills, retouchings and overpaints and with the aid of early documentation and art historical research, inpaint the blockjoins and reintegrate the most disfiguring losses. The paintings could be treated horizontally or vertically because of the earlier divisions and mountings, thus facilitating all stages of the treatment and allowing the innovative techniques. Cleaning was carried out under individualized plexiglass fume extraction chambers, and cleavage was set down under wire-less fiberglass heat blankets using an acrylic emulsion.