Abstract: A substantially uniformly coated substrate that may be either metallic or ceramic in nature as well as a process for preparing such coated substrate. The substantially uniformly coated substrate typically comprises a plurality of outlets; a plurality of substrate walls; and a plurality of channels defined by the substrate walls, said channels extending directly or indirectly from at least one outlet; and wherein there are a plurality of openings and/or corrugations and/or tabs in the substrate walls that communicate between adjacent channels, said substrate containing at least one substantially uniform layer of a coating material that may be a non-sorbent, non-catalytic material; a sorbent, non-catalytic material; a catalytic material or a mixture of two or more of the foregoing materials.