Methods of manufacturing a ceramic honeycomb body having a honeycomb structure with a matrix of intersecting walls, and a skin disposed on an outer peripheral portion of the matrix where the skin has a first average porosity and the interior portion of the matrix has a second average porosity that is greater than the first average porosity. The methods include coating at least the skin with a fluid formulation containing a sintering aid and subsequently firing the honeycomb structure. In certain embodiments, a glass layer is formed in the skin or in regions of the walls directly adjacent to the skin. In certain embodiments, the coating is applied to a green honeycomb structure, and in other embodiments the coating is applied to a ceramic honeycomb structure. Other honeycomb bodies and methods are described.