A clip constructed of resilient material slidably engages the door of a paper web drive tractor of a printer. The clip defines two reference edges which are spaced by an amount substantially equivalent to the distance between a type line reference rod and the print line of a print mechanism. The operator aligns a selected type row on the web with the reference rod and slides one reference edge adjacent a mark on the web. The web is moved until the mark is aligned with the other reference edge of the clip and the selected type row is thereby positioned on the print line.