Polylines (single sided polygons, a polygon with two vertices) do not always print to an ImageWriter LQ. The full scope of this problem is not known. However, under the following test conditions, a horizontal polyline did not print, while a diagonal polyline did print:
MacDraw Pro 1.5v1/v2
AppleTalk ImageWriter 7.0
System 7.01
Pen Width 0.0001 inch
Pen Color black
This file prints correctly to various other printers.