Abstract: A procedure is provided for adjusting for image line skew caused by tolerance accumulation between a Raster Output Scanning (ROS) assembly and a photoreceptor which is being scanned. The ROS housing is adjustably mounted in relation to the photoreceptor, so that incremental adjustments can be made to cause the output scan lines emerging from the ROS housing to be moved in the process or reverse process direction vis-a-vis the photoreceptor. A test print is generated which provides measurable scan delineators to identify the amount of scan line skew created by a photoreceptor misalignment. The measured scan line skew alignment is correlated with adjustments made by a hex head screw to provide a very precise alignment. The effective adjustment range is .+-.4 mm in the process direction which corresponds to .+-.6.3 milliradians of scan line skew.