A method for preparing a coated substrate that includes (a) applying a photoinitiator to a surface of a substrate; (b) exposing the photoinitiator to ultraviolet or ultraviolet-visible radiation to activate the photoinitiator and form a pre-treated surface; and (c) applying a coating composition to the pre-treated substrate to form a coated substrate. The coating composition may be a nanoparticle-containing emulsion.