Can anyone give me some example how I use the parameter "blankTile"? Do I attach that request at the end of http://<imageservice-url>/tile/<level>/<row>/<column>?
I've moved your post into the Arcgis Rest API space. You will get a much better answer here as the GeoNet Help is intended for community help and feedback. I have also added in a few additional tags. You can see more
on the community structure, and what topics are under each space from the following documents:
ArcGIS Discussion Forums Migration Strategy
Thanks!
Don