Dear colleagues I am using AutoCAD R14 to design a mask set. As the set is a particularly complex one, this makes it difficult to detect and correct errors. The set has been sent to our mask makers, who have detected a number of 'open polyline objects' within the design. Unfortunately, the mask makers cannot specify where the open polylines are within the set. It should be noted that the ebeam cannot write open polyline objects of zero width when writing the masks. I have been told that there is a way within AutoCAD to select and display open polyline objects, but I am not too sure how to do this. There is an option for selecting polylines but it seems that there is no option for selecting open ones from closed ones. If anyone has any suggestions - please let me know ? Many thanks Richard Haigh