《明史·志·卷三十六》
内棺外椁，品级官内棺用油杉制造用朱红漆涂刷，外棺用土杉制成。
棺椁，品官棺用油杉朱漆，椁用土杉。
The outer coffin is used for the inner coffin; the inner coffin for officials with rank is made of oiled fir and painted with vermilion lacquer, and the outer coffin is made of Chinese fir.