Image Hotspots

Is it possible to create a transparent icon in the Image Hotspot tool? This should be easy as the clickable areas are transparent in the Find Multiple Hotspot tool.

Basically, I want the advanced options for what happens in the Image Hot Spot Tool, like the option for adding text or images once you click on the hot spot, but I don't want the students to know where the hot spots are, they have to find them - hence the transparent icons.

I am a new user and would like to know if I need to purchase an account to create different content? 

In developing an "image hotspot", the background image is huge. How could we reduce the size of the background image .