Various silicone–acrylic block copolymers were prepared by a free radical copolymerization technique, in which we used poly(dimethyl-siloxane) containing azo groups as a macromolecular initiator in reactions with acrylic monomers, including functional monomers. The copolymer solutions were coated onto substrates by using various application methods and subsequently cured by using either crosslinking agents or UV light. Advancing (_A) and receding ( _R) contact angles of the resulting films were measured in various inks. These films were found to be hard enough to form a nozzle face, and exhibited over 80° of  _A and 60° of _R when in an ink, which are superior values to those observed for silicone or fluorinated coating films. The ink resistance of the films was evaluated by changes in _A and  _R before and after soaking the films in various inks at 60°C for 4 weeks. The durability of the films was outstanding. The excellent properties were found to be attributable to the formation of a microdomain structure, and to be influenced by domain spacing rather than silicone content.