Slitherine

I have noticed many scenarios have a template that can be brought up while creating the map. My questions is where are these made? I could really see this helping with my layouts and wanted to get some info on how they are made. I attached an example to the post.

It is simply a jpg file named template. You use ctlr t to turn it on/off.
The template may come from various sources, search the web for the specific battle you're making and check all picture files. Usually there are several maps available. The trick is to find a map with clear terrain, important towns and roads/rails.