To enable an optimal transfer correction value to be easily established with high precision by specifying the transfer error caused by the individual difference of a means for transferring a recorded material in the sub-scanning direction for every recording device.

An inkjet type recorder 50 is made to perform a printing only with a black ink, according to a test-pattern recording control data with which test patterns T1-T7 are recorded by setting the transfer correction value AN as a zero standard and changing the value to 7 stages of +1 to +3 and -1 to -3 with a constant step. The test pattern recorded with the suitable transfer correction value corresponds to the state that each of lapped rasters has been lapped completely in agreement in the sub-scanning direction Y. For the test pattern in which the transfer correction value AN is relatively close to a proper value, since each of the rasters of the lapped portion of the raster group is lapped nearly in agreement, the lapped portion of the test pattern is visible as a light gray color. The test pattern, in which the lapping gap between rasters is large and the transfer correction value AN deviates a little from the proper correction value AN, is visible as a deep gray color.