Images, one per page, are printed by a digital printer consecutively on a web of paper fed to travel forward. A timing mark is printed for each image. In case printing is temporarily halted, the web of paper is first fed backward, and then it is fed forward again. The number of timing marks in each of the backward feed and forward feed of the web of paper are counted. When the number of counts of the timing marks counted in the forward feed coincides with the number of counts of the timing marks counted earlier in the backward feed, printing of consecutive images is reinitiated from a position immediately following an image last printed before printing was temporarily halted.