Everyone uses the polyline LT Enable and Disable settings for even spaces for dashes in polylines, but did you know that an open dashed polyline can be controlled with another factor? Sometimes the spaces fall in an open part of the dashed line that you would like to be solid. Here is the quick fix. Let’s say your polyline width is 5.0; click on the Properties box and change the starting width to 4.99. This will create a solid line at each and every vertex, making a neat corner for each bend in the polyline. It does not work on closed polylines.
Notes from Cadalyst tip reviewer R.K. McSwain: Since you are setting the start and end values of each segment to different values, even if the difference is so slight to not be visually noticed, AutoCAD will always start a new segment where it might otherwise leave a gap. It seems to give the same result as disabling the linetype generation setting, but it may give various results depending on the geometry.