If you have a bad quality of the vector layer in your output, the layers might have been rastered, even though no raster layers have been used. By using the arcpy script DetectRasterization you can check, if some layers will be pixelated (caused by symbology or other settings).
This script can be copied from the ArcGIS help (please scroll to chapter Troubleshooting map printing): Printed map appears blocky or pixelated - Rasterization. The script detects, if a layer causes rasterization.
The essential steps to do are:
- open MXD
- copy arcpy script to python window and execute
- If a layer causes rasterization, there will be a message like: In data frame 'Layers', the layer 'Basiskarte\Grenzen\LNDGEN_PL: 1.500.000-1.280.000' is a rasterizing layer: Visibility is True.Transparency is 60 percent.
- The reason for rasterization must be corrected in order to get an optimized print output.