A thermal transfer printing apparatus configured to acquire data on a color of a first image and data on a color of a second image, adjust a portion of the data on the color of the first image thus acquired and a portion of the data on the color of the second image thus acquired using a predetermined density adjustment parameter, and perform a panoramic image printing process of printing the first image and the second image using a plurality of printing surfaces arranged on an ink sheet to cause the portion of the first image thus adjusted and the portion of the second image thus adjusted to be superimposed on each other, the thermal transfer printing apparatus comprising: a divided image data acquisition part configured to acquire data representing a first-page calibration image including data on a color density of a plurality of first-page calibration patterns and data representing a second-page calibration image including data on a color density of a plurality of second-page calibration patterns; a calibration-use density adjustment parameter storage part configured to store a plurality of the density adjustment parameters that are each associated with a corresponding one of the plurality of first-page calibration patterns and the plurality of second-page calibration patterns; a density adjustment processing part configured to adjust data on a color density of a first-page superimposing portion that is superimposed on a corresponding one of the plurality of second-page calibration patterns during printing of the data on the color density of the plurality of first-page calibration patterns using one of the density adjustment parameters associated with a corresponding one of the first-page calibration patterns and adjust data on a color density of a second-page superimposing portion that is superimposed on a corresponding one of the plurality of first-page calibration patterns during printing of the data on the color density of the plurality of second-page calibration patterns using one of the plurality of density adjustment parameters associated with a corresponding one of the second-page calibration patterns; and a printing part configured to print the first-page calibration image and the second-page calibration image on recording paper to form a plurality of printed calibration patterns that are each constituted by one of the first-page calibration patterns and one of the second-page calibration patterns and include a printed superimposing portion where the first-page superimposing portion and the second-page superimposing portion are superimposed on each other based on the data on the color densities adjusted by the density adjustment processing part, wherein a color density of the printed superimposing portion printed on the recording paper varies for each of the printed calibration patterns. a divided image data acquisition part configured to acquire data representing a first-page calibration image including data on a color density of a plurality of first-page calibration patterns and data representing a second-page calibration image including data on a color density of a plurality of second-page calibration patterns; a calibration-use density adjustment parameter storage part configured to store a plurality of the density adjustment parameters that are each associated with a corresponding one of the plurality of first-page calibration patterns and the plurality of second-page calibration patterns; a density adjustment processing part configured to adjust data on a color density of a first-page superimposing portion that is superimposed on a corresponding one of the plurality of second-page calibration patterns during printing of the data on the color density of the plurality of first-page calibration patterns using one of the density adjustment parameters associated with a corresponding one of the first-page calibration patterns and adjust data on a color density of a second-page superimposing portion that is superimposed on a corresponding one of the plurality of first-page calibration patterns during printing of the data on the color density of the plurality of second-page calibration patterns using one of the plurality of density adjustment parameters associated with a corresponding one of the second-page calibration patterns; and a printing part configured to print the first-page calibration image and the second-page calibration image on recording paper to form a plurality of printed calibration patterns that are each constituted by one of the first-page calibration patterns and one of the second-page calibration patterns and include a printed superimposing portion where the first-page superimposing portion and the second-page superimposing portion are superimposed on each other based on the data on the color densities adjusted by the density adjustment processing part, wherein a color density of the printed superimposing portion printed on the recording paper varies for each of the printed calibration patterns.