How can't some redundant lines be deleted in proe engineering drawings?

There are several possibilities: 1, the feature does not form a closed solid or has a broken surface, which needs to be repaired before it can be completed (this problem may exist if lines of other colors except the outline can be seen after blanking in the part drawing) 2. In the process of drawing the feature part, the surface will be drawn, but the surface will not be hidden. At this time, it may also appear in cad. Under normal circumstances, if there is only a white outline in the part drawing after blanking, what you said will not happen generally!