behind a solid shape.
Here is when a window template in the exact size of that part of your project,
that you can move across the paper background will show you how it will appear
before you cut it out.
Use the template for the card (print an extra copy so you can cut it open)
to make a window template. Move it across your chosen background
until you see a pleasing effect.
I use this method with a hollow 2.5" X 3.5: hollow frame when I make ATC's
It really works to isolate a pleasing aspect of the image you have chosen.
The waterfall isolated for an ATC Background.