Abstract: A method of manufacturing a fibrous material includes mixing at least two cordierite precursor materials to form a mixture. One or more of the at least two cordierite precursor materials is in a form of a fiber and the mixture includes about 43% to about 51% by weight SiO2, about 36% to about 41% by weight Al2O3, and about 12% to about 16% by weight MgO. The method also includes extruding the mixture to create a fibrous body, and heat treating the fibrous body, at a temperature of about 1200° C. to about 1420° C., to form the fibrous material including about 50% to about 95% by weight cordierite. A fibrous body includes an extruded substrate having a plurality of fibers including about 50% to about 95% by weight cordierite. The extruded substrate has a coefficient of thermal expansion in at least one direction of less than about 3.8·10?6 per ° C.