1. A method of correcting output image squareness in a laser printer system having a Raster Output Scanning (ROS) device comprising: (a) pivotally mounting said ROS device; (b) printing a test pattern including a plurality of predetermined markers; (c) measuring a plurality of distances between said markers; (d) calculating a skew angle based plurality of distances; and (g) rotating said ROS device by an amount sufficient to correct said skew angle.