Abstract: The present invention concerns a method of modifying the surface of a cellulosic material, wherein a modifying compound is attached to the cellulosic material through a linker, which linker is a conjugate that has been activated by functionalization prior to adsorption to form an activated conjugate, and wherein the entire method is carried out in aqueous media, as well as an intermediate product suitable for attaching to a modifying compound, the intermediate product comprising said functionalized conjugate linker that has been adsorbed to a cellulosic material.