What causes spikes, spurs, artifacts, drop out and other distortions to occur on paths? 


1. Paths are too complex or points are not at extrema. Use Element > Clean Up Paths repeatedly until paths are fixed. As needed, use Edit > Undo to back up to the last step which preserves the character shape. 
2. There may be broken paths, paths on top of paths, adjacent points, or twisted BCP handles. Paths can be rejoined. Duplicate paths can be deleted. Unneded points on a path can be deleted. Twisted BCP handles can be rotated around 180° until they are faceing the right way.
3. Hinting can cause spikes at print time. This can be isolated by turning hints OFF when generating a test font. If that makes the problem go away, there is an issue with the hinting. This can be related to poor outline construction as well—look for points that are on top of or only one or two units away from another point. If these are the spike locations, you may need to delete or move points.
4. Sometimes a particular printer driver can cause spikes. Search the manufacturer's web site for the latest printer driver available. 
5. Thickening of characters can occur if the path direction is incorrect. Select Element>Correct Path Direction. 
6. Unusual shapes may require adding an additional point (or two) to the problem area.
7. For TrueType fonts, Dropout Prevention may help. This feature is found in the Advanced Generate dialog under the “TrueType Options” button. 
8. If none of the above techniques seem to help, there may be a stray point elsewhere in the problem glyph. Zoom out and inspect the font's outline window in order to look for loose points.