I took some picture frames I got a a yard sale, some spray paint, a set of shears and a staple gun.
A roll of aluminum screen (like you put in doors and windows.
I painted the screen.
In contrasting colors...
Then I cut the screen out and stapled it to the back of the frame with the contrasting color.
It might be hard to see but the red frame had turquoise screen, turquoise frame has red screen, black frame has turquoise screen and the fancy frame has black screen.