Thermal transfer printing method and apparatus are provided to make initial character image data left on a spent ink ribbon illegible. In the method, after forming an initial character image on an ink layer in black of the ink ribbon, a forefront of the ink layer is aligned with a forefront position of an intermediate transfer film. Then, overwrite character image data is applied on a thermal head to produce a first superimpose character image on the ribbon and a first superimpose character image on the film. After that, the forefront position of the ink layer is shifted from the forefront position of the film by a predetermined distance and the overwrite character image data is applied on the thermal head to produce a second superimpose character image on the ribbon and a second superimpose character image on the film.