This document concerns the investigation of techniques and materials of late 19th century Thai murals and a comparison with those of earlier period murals from previous studies. It shows that the techniques of paintings are the same except in one case. However, there were changes in the use of pigments. From the early 19th century there was some western influence on the use of pigments and this increased significantly in the late 19th century. Materials found in Thai murals of various periods are summarized and reported. Lead dioxide is detected in this study as possible alternative to minimum. Lead dioxide is detected in this study as a possible alternative to cinnabar.