Abstract: A high temperature resistant seal for a catalytic converter is made from a high temperature resistant material including between approximately 28 and 60 dry weight percent high temperature resistant ceramic fibers and between approximately 20 and 50 dry weight percent high aspect ratio vermiculite. The seal is formed by mixing the resistant ceramic fibers with an aqueous dispersion of high aspect ratio vermiculite, applying the resultant mixture to a monolithic catalyst structure of a catalytic converter and heating the mixture and the monolithic catalyst structure to evaporate the water from the mixture. The seal and the monolithic catalyst structure can then be assembled in a housing to form a catalytic converter.