Low cost aluminosilicate fibers are used to form a ceramic substrate material using inorganic binders that promote the formation of stable compounds that inhibit the formation of crystal silica, or cristobalite, when the substrate is used or exposed to high operating temperatures. The aluminosilicate fibers are mixed with additives including organic and inorganic binders and a fluid to form a plastic mixture. The plastic mixture is formed into a green substrate, and subsequently cured into the ceramic substrate. The fiber-based constituents permit the formation of rigid porous structures for filtration, insulation, and high temperature processes and chemical reactions.