PDF map does not match viewer when printing at high resolution

When I print the map at high resolution, the resulting map doesn't match what I see on the screen.  Why is that?

Geocortex Essentials performs high resolution printing by generating a PDF (using a template) which includes a translated version of the map image shown to the user.  In order to provide this image at high resolution, it must have its resolution (DPI) increased – screen resolution is 96dpi.

When your map uses ArcGIS server dynamic services, we can simply request a new image from the service at the desired DPI.  The server will scale up the symbols and renderers to suit our requested DPI, and show layers visible at the requested scale.  If you print at "current scale", then your printed map will match your onscreen map.

However, when your site includes a cached service, then ArcGIS Server will NOT scale up the symbols when we request a higher resolution.  Instead, it will use the pre-cached images to generate a high resolution image.  Consequently, it may  select tiles from a different scale level to draw the map.

The end result is a high resolution PDF map that may not match the map seen on screen.  At the very least, lines and text symbols will appear smaller, as they will have been scaled appropriately for screen resolution at the various scale levels.  At worst, the user will see a totally different map, due to scale dependent renderers and layers.

To avoid this behavior, you must use 96DPI when generating a PDF using cached services.