Provided is a composition for a printing medium and a printing medium that can be suitably used for a plurality of printing methods, including a plurality of plateless printing methods such as thermal transfer printing, electrophotographic printing, and inkjet printing methods. A coating layer is provided on at least one surface of a support body, and includes (a) a cationic urethane-based resin, (b) an olefin copolymer emulsion, and (c) an ethyleneimine-based resin. The solid mass of the coating layer on one surface of the support body may be 0.01-5 g/m2.