Abstract: A method for surface treatment of a paper substrate and a paper product produced therefrom are disclosed herein. The surface treatment method includes applying a salt-containing solution to at least one surface of a paper substrate by aerosol spraying in a separate step, whereby the salt distribution through the thickness of the treated paper substrate is non-uniform with the highest concentration of salt being present in the outermost portion of the paper substrate. The salt-containing solution contains at least one water-soluble metal salt and is void of any optical brightening agent (OBA).