an ink donor sheet recording medium is disclosed . the medium is comprised of a paper base which has a solidified ink layer formed on one surface . the paper base is rendered moisture proof by providing a dampproof layer on the surface opposite the ink layer or by incorporating a hydrophobic compound within the paper . by rendering the medium moisture proof the medium can be used under adverse humidity conditions without being physically distorted . accordingly , the medium can form clear sharp images even when used in adverse humidity conditions .