In general, one aspect of the technology described can be embodied in methods that include the action of applying a writing mechanism having non-isotropic writing properties resulting from different degrees of coherence interaction in a sweep direction and a cross-sweep direction, writing an image pattern twice on a work piece using the writing mechanism rotated relative to the image pattern written on the workpiece between first and second writings, whereby writing with the rotated writing mechanism averages the non-isotropic properties. The lesser included angle separating first and second relative directions of movement between a workpiece and writing mechanism may be 20 degrees or greater, or somewhat less, under conditions described herein.