The attached image depicts the problem. On the left (gray background) is original image as seen in DraftSight window while editing the source (.dwg) file. On the right (white background) is the image of the exported .pdf file as seen in many pdf viewers. As you can see the black filled areas are all distorted in pdf file. I am using "DraftSight 2015 x64 SP1". I have updated the software from version "DraftSight V1R5.1 x64" - no problems with pdf image quality in this older version. I do not know how to download the older version and how to configre (if possible) the newest software to produce quality pdf file.