The present invention is drawn to a method of preparing a porous media substrate, comprising combining metal or semi-metal oxide particulates with a polymeric binder, wherein the metal or semi-metal oxide particulates are associated with at least one water soluble coating formulation additive. At least a portion of the water soluble coating formulation additive i) is in the form of unreacted additive, or ii) generates undesired electrolytes. Additional steps include removing at least a portion of the unreacted additive or undesired electrolytes, either before or after combining the metal or semi-metal oxide particulates with the polymeric binder, thereby forming a refined coating composition; and applying the refined coating composition to a media substrate to form an ink-receiving layer having a porous surface.