When using the Print Task in an ArcGIS Server .NET web application, the output map may appear blank if the web application is zoomed in to the largest cache scale. If the map is zoomed out to the next cache scale, the map in the Print output is viewable.
This behavior occurs when the Print Quality is set to Normal while configuring the Print Task.
The Print Quality values, Normal and Draft, represent the resolution of the output map.
Normal print quality uses 200 DPI. In order to create a map with this resolution and preserve the map extent, cache tiles from larger scales must be used. When the application is zoomed in to the largest scale, the print task requests tiles from a larger scale. Since no cache tiles are available, the output map is blank.
Draft print quality uses 96 DPI, which is the default DPI for caching and is the same DPI used by ArcGIS Online Services. The print task does not need to use cache tiles from another scale, so the tiles are always retrieved correctly. In most cases, Draft quality is suitable for map printouts.
If Normal print quality is needed, the web application should either use a dynamic service or a cached map service with tiles created at 200 DPI. A cache with such a high resolution takes up more space on the hard drive.