We demonstrate that the degree of hydrogenation of graphene directly controls the grafting density and thus, the layer thickness of grafted polymer brushes synthesized via self-initiated photografting and photopolymerization. Among the tested monomers, only styrene derivatives could be directly grafted onto copper-supported graphene. Therefore, copolymerization of styrene and acrylates, as well as consecutive grafting of both monomer types, was employed to realize functional polymer brushes of poly(styrene-co-acrylate) copolymers. The direct grafting of polymers on graphene results in polymer carpets that are suitable for a wide variety of applications.